Let’s fix the apc_index_mismatch error on Windows with this article. Bobcares, as a part of our Server Management Services, offers solutions to every query that comes our way.
What Is
apc_index_mismatch
Error On Windows?
apc_index_mismatchWhen certain conditions meet, some functions execute outside the main program. Those functions are called Asynchronous Procedure Call (APC). Many blue screen errors occur due to
apc_index_mismatchissues. The
apc_index_mismatchusually occurs due to problematic hardware or incompatible drivers.
The APC Index Mismatch error typically denotes a disparity in the number of processes that entered and exited an operational area where a program is running. As a result, the system crashes with a BSOD. This is essentially the operating system informing us that it cannot run software without avoiding the risk of harming the system.
How To Fix The Error?
Some of the methods to fix the error are as follows:
1. Keep the OS updated
We’ve to make sure the installed Windows is the latest version. If not, we’ve to do it as an operating system update may fix a lot of issues including the APC Index Mismatch blue screen error.
2. Examine the RAM and modify the frequency as needed
Revert to the default frequencies and check to see if the BSOD crash is resolved if we overclocked the CPU, GPU, or RAM frequencies. If the issue has been resolved, excessive overclocking might have been the root of it. Try to gradually raise the frequencies once more, but only by a small percentage at a time.
3. Check your PC for new updates
- Right-click the Start menu and choose Settings to check for the new driver and system updates.
- Choose Update & Security > Windows Update under Settings. Windows need to launch a scan for a fresh system and the driver updates automatically. Select the Check for Updates button if it doesn’t. If not, choose Download (or Download and Install) to start the installation of fresh updates.
- By choosing View options updates from the Windows Update menu, we might also need to choose and install any optional driver updates for the computer that might address stability issues.
If the above steps didn’t fix the error, we need to analyze the memory dump files to determine which driver is causing the problem. After finding the driver or the device, we can manually update it.
4. System maintenance
It’s a good idea to keep up with system maintenance to avoid BSOD errors. To make sure they are operating properly, we might want to automatically update high-priority drivers like the graphics card drivers. We can always use some common PC repair tools to test and conduct further troubleshooting if the computer stops functioning.
5. Update the outdated audio drivers
Considering Realtek components, an outdated audio driver may be the main cause of the blue screen of death errors. In such a case, we can go to the official site of Realtek and download the new updates. We need to restart the system to apply the installation.
6. By using the blue screen troubleshooter
The blue screen troubleshooter can fix the apc_index_mismatch errors. Even though the troubleshooter might not be able to recover the files and work that we lost as a result of the system crash error, it might be able to stop one from happening again.
[Looking for a solution to another query? We are just a click away.]
Conclusion
To sum up, our Support team went over the details of the Windows error “apc_index_mismatch” along with 6 simple solutions to fix the error.
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Contents
- What are the common causes of the «APC_INDEX_MISMATCH» (0x00000001) error?
- Restore Deleted Files
- Start The Computer in Safe Mode
- Update a Driver With The Device Manager
- Use sfc /scannow To Check All System Files
- Check for Errors The Disk Where Windows Is Installed By Using The Command chkdsk c: /f
- Use The Mode of Compatibility With an Old Version of Windows
- Disable Unnecessary Programs in Windows Startup Menu
- Consult Microsoft Support Service
- Install Latest System Updates
- Scan The System For Viruses
- Test Your RAM
- Make a Clean Installation of Windows
What are the common causes of the «APC_INDEX_MISMATCH» (0x00000001) error?
The common causes of the «APC_INDEX_MISMATCH» (0x00000001) error include:
- Corrupt system files: If system files are corrupted or damaged, it can lead to the «APC_INDEX_MISMATCH» error.
- Outdated or incompatible device drivers: If device drivers are outdated or incompatible with the operating system, it can trigger the error.
- Hardware issues: Faulty hardware components, such as RAM, hard drive, or CPU, can also cause the «APC_INDEX_MISMATCH» error.
- Software conflicts: Conflicts between different software applications or programs can result in the error.
- Malware infections: Malware or viruses can corrupt system files and cause various errors, including «APC_INDEX_MISMATCH».
- Overclocking: Overclocking the CPU or other hardware components beyond their recommended limits can lead to system instability and errors.
- Registry errors: Issues in the Windows registry, such as invalid entries or missing keys, can trigger the «APC_INDEX_MISMATCH» error.
- Incompatible Windows updates: Installing incompatible or buggy Windows updates can also cause the error to occur.
Also:
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There is not enough free space in the hard disk of your computer/laptop. For Windows 10 to operate correctly you need to have from 2 to 10 Gb of free space in your system disk.
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An incompatible version of BIOS was installed or the firmware was damaged.
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Device drivers incompatible with the OS were installed.
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Windows registry was damaged or deleted, or cleaning operations accidentally deleted system keys.
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Antivirus software or viruses may block system files or delete important registry keys.
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An error occurred in the work of backup software.
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It can also happen as a result of a Windows update.
Read more how to fix 0x00000001: «APC_INDEX_MISMATCH» in Windows 11, Windows 10, Windows 8.1, Windows Server 2012, Windows 8, Windows Home Server 2011, Windows 7 (Seven), Windows Small Business Server, Windows Server 2008, Windows Home Server, Windows Vista, Windows XP, Windows 2000, Windows NT.
Here are some ways of eliminating the problem with «APC_INDEX_MISMATCH»:
Restore Deleted Files
Often BSoD errors cause loss of important files. Files blocked by computer viruses, backup software errors, damaged or overwritten system files, file system errors or bad hard disk sectors – these are only some of the causes that can make your data lost.
Corrections of the corresponding errors will restore the normal operation of your devices, but it does not always restore damaged or lost files. Also, it is not always possible to eliminate an error without formatting the hard disk or clean installation of the operating system, which can also involve loss of files.
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Start The Computer in Safe Mode
If the error «APC_INDEX_MISMATCH» (0x00000001) occurs when loading Windows and blocks any attempts to work with the system, try loading the computer in Safe Mode. This mode is meant for operating system (OS) diagnostics, but OS functions are very limited in this mode. Safe Mode should only be used if the system is blocked otherwise.
In order to start Safe Mode you should do the following:
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Go to Start menu and choose Settings.
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In the settings window that appears go to Update & Security menu and choose the Recovery tab.
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In the tab Recovery find Advanced startup and click the button Restart now.
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As your Windows restarts, it will ask you to choose the next step. Choose Troubleshoot.
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In the Troubleshoot menu click on Advanced Options and then on Startup Settings.
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Then Windows will inform you that the computer can be restarted with the use of additional settings one of which is Enable Safe Mode. Press Restart.
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After restarting choose Enable Safe Mode by pressing F4.
Go to view
How to Boot Windows 10 in Safe Mode (All Methods)
Update a Driver With The Device Manager
Have you installed new hardware to your computer? Are you using a new USB device? These can be the causes for the error «APC_INDEX_MISMATCH». If you installed your device driver from the disk you have found in the device delivery package or if you are using a driver which was downloaded from a place other than Microsoft official website, this can be the core of the problem. You will have to update the device driver to fix it.
You can do it manually in the Windows device manager by taking the following steps:
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Press Windows button and type device manager on the keyboard.
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Choose Device Manager from the list.
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View the list of device categories and click on the arrow nest to the category in which your new device falls. The driver can be marked with a yellow triangle.
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Right-click on the device name and press Update Driver Software.
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Then a window of Update Driver Software with two options will appear:
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Search automatically for updated driver software. Windows will automatically check availability of the best suitable driver for this device.
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Browse my computer for driver software. Use this option to show the OS where the driver files are kept.
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Restart the computer after the driver is installed.
Use sfc /scannow To Check All System Files
Damaged or rewritten system files may cause the error «APC_INDEX_MISMATCH». The command sfc finds damaged Windows system files and replaces them.
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Press Windows button and enter cmd from the keyboard.
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Right-click on CMD and launch it as administrator.
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In the command prompt window, type in sfc /scannow and press Enter.
This process may take several minutes.
Go to view
How to Recover Windows 10, 8, 7 System Files (SFC, DISM)
Check for Errors The Disk Where Windows Is Installed By Using The Command chkdsk c: /f
The blue screen with «APC_INDEX_MISMATCH» may be caused by a file system error or by bad sectors in your disk. The command CHKDSK will check the disk for file system errors and bad sectors. Using the setting /f will make the program to automatically correct the detected errors, and the setting /r allows finding and fixing problem disk sectors. To launch it, follow these steps:
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Press Windows, then enter CMD from the keyboard.
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Right-click on CMD and launch it as administrator.
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In the command prompt window type chkdsk c: /f and press Enter (use the letter of the drive where your OS is installed).
Wait until the process is over and restart your computer.
Use The Mode of Compatibility With an Old Version of Windows
A error with the code «APC_INDEX_MISMATCH» may be caused by outdated software. If this error occurs after launching a program, then using Windows compatibility mode can help you get rid of the problem. To fix it, do the following:
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Find a program executable file (it has .exe extension) and right-click on it.
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In the quick menu, select Troubleshoot compatibility.
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At the next stage, you will see the window Program Compatibility Troubleshooter. You will have two troubleshooting options to choose from:
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Try recommended settings. Select this variant to start a test run of the program using recommended compatibility settings.
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Troubleshoot program. Select this variant to choose compatibility settings based on what problems you have encountered.
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After testing the program under various versions of Windows and startup settings save the suitable settings for your program.
Go to view
How to Run a Program in Compatibility Mode With Windows 10, 8 and 7
Disable Unnecessary Programs in Windows Startup Menu
The software causing «APC_INDEX_MISMATCH» (0x00000001) may be written to Windows Startup list so the error occurs immediately after the system starts without any user activity. You can delete programs from Startup by using Task Manager.
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Load the computer in Safe Mode.
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Right-click on Task Bar and then on Task Manager.
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Go to Startup tab.
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To delete a program from the startup list select it and disable by clicking Disable in the right lower corner of the window.
Consult Microsoft Support Service
Microsoft offers several solutions to eliminate the blue screen error. «APC_INDEX_MISMATCH» (0x00000001) can be fixed with the help of Windows Update or by addressing Windows Support.
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Go to Microsoft Support Service.
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Enter your error code and message into the search field and follow the directions.
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If you don’t find a ready solution as the community where your query can be answered by a certified system administrator.
Install Latest System Updates
Windows provides updates that extend your driver database and correct errors or security vulnerabilities. Download the latest updates to get rid of the error «APC_INDEX_MISMATCH» (0x00000001).
You can launch Windows Update like this:
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Go to Start menu and select Settings.
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In the Settings window go to Update and Security tab.
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To install the latest Windows updates click on Check for updates and wait until they are found and installed.
It is recommended to set up automatic download and installation of system updates with the help of Advanced Options.
To enable automatic system update you need to start Windows Update:
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Go to Start menu and choose Settings.
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In the Settings window go to the Update and Security menu and select Windows Update. To install the latest Windows updates click on Check for updates and wait until they are found and installed.
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Go to Advanced Options and choose the mode of update installation — Automatic.
Scan The System For Viruses
The blue screen of death with the error «APC_INDEX_MISMATCH» 0x00000001 can be caused by computer viruses that infected your system.
To check the computer for viruses launch your antivirus program.
Modern antiviruses allow checking both hard disks and RAM. Run a full system scan.
Test Your RAM
System memory problems may cause errors, loss of data or even make your computer stop working.
Before you start checking RAM, take it out of the slot on the motherboard and then stick it back again. Sometimes the error «APC_INDEX_MISMATCH» can be caused by the memory stick which was set into the slot incorrectly or not tight enough, and sometimes by the slot contacts covered with dust.
If the above actions did not make things better, you can check your RAM with the means of your operating system – Windows Memory Diagnostic.
JYou can start this tool in two ways:
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With the help of Control Panel:
Go to Control Panel / System and Security / Administrative Tools. Launch the application Windows Memory Diagnostic.
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With the use of Run:
Launch the Run tool with the combination of keys Windows + R. Type in mdsched and press Enter. The Windows Diagnostic tool will start.
To start the checking select one of the suggested variants to decide how your RAM will be tested after the computer is restarted.
If the diagnostic tool finds errors that cannot be corrected, such memory should be replaced (that is, you have to replace the memory stick where errors were found).
Make a Clean Installation of Windows
If none of the methods helped you to get rid of «APC_INDEX_MISMATCH», try reinstalling Windows. In order to make a clean installation of Windows you need to create a setup disk or another media which you are going to use to install the OS.
Start the computer with the setup disk. To do it you may need to change boot priority in BIOS or UEFI for newer computers.
Following the installer menu stages, specify the disk where you want your Windows installed. You will have to format it then. If you are not satisfied with the number or size of the local disks they can be deleted and repartitioned.
Remember that formatting, deleting or partitioning your disks will destroy all files in the hard disk.
After specifying the disk to install Windows to, the process of copying system files and installing the operating system will start. During the installation, no additional action is required. In the process, the screen will go off for a while several times, and the computer will restart on its own to complete certain stages of installation.
Depending on the version of Windows at one of the stages you may have to select or enter basic personalization settings, choose how the computer works with networks and select settings of your account or create a new one.
As the computer loads the desktop, a clean installation of Windows is finished.
Note. Before you start a clean installation of Windows make sure you have drivers for all your hardware and that your files are safe. Download and save drivers to a separate media, and create a backup copy of important data.
Go to view
How to Reset Windows 10 or 8 PC to Factory Default Settings (All Methods)
Go to view
How to Reset Windows 10 or 8 PC If The Operating System Won’t Boot
Содержание статьи:
- Рекомендации
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- ШАГ 2
- ШАГ 3
- ШАГ 4
- ШАГ 5
- ШАГ 6
- Вопросы и ответы: 0
Вопрос от пользователя
Здравствуйте.
Помогите с одной проблемой…
Пытаюсь распечатать документ на ПК — вылетает синий экран с кодом ошибки «apc index mismatch». Пытался уже переустанавливать принтер, печатать из разных программ, создавать нового пользователя и т.д. — всё без толку.
Сам принтер проверял (попросил соседа подкл. принтер к его ноуту — у него все норм. печатает на него).
На всякий: Windows 10, AMD Ryzen 3400G, 16 ГБ ОЗУ 3200 Mhz Hynix, KYOCERA FS-1120 (A4).
Здравствуйте!
Я тоже в начале марта столкнулся с подобной проблемой, правда не особо «пострадал» (но вероятно, что причины у нас с вами совпали 😉). Дело в том, что в первых числах марта у Microsoft было «некорректное» обновление, которое и вызывало данную проблему (не у всех принтеров, но всё же…).
Ниже в заметке предложу несколько способов решения (+ возможные доп. причины, не связанные с принтером).
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Пример ошибки «APC_INDEX_MISMATCH» с синим экраном
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Рекомендации
ШАГ 1
Этот способ решения универсальный. Подходит в тех случаях, когда синие экраны начали «сыпаться» внезапно, после какого-то обновления ОС. Удалив в этом случае это самое последнее обновление — часто проблема тут же пропадает!
Для начала сразу же приведу мартовский список «проблемных» обновлений (связанных с печатью):
- KB5000802 (у версии 2004/20H2);
- KB5000808 (у версии 1909);
- KB5000809 (у версии 1809);
- KB5000822 (у версии 1803).
- Прим.: 👉 как узнать свою версию ОС.
- Прим. 2: разумеется, если вы столкнётесь с подобной ошибкой намного позже даты публикации этой заметки — «виновниками» в вашем случае могут быть др. обновления!
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Что нам дает этот перечень?
Да можно просто открыть список установленных обновлений, отсортировать его по дате, и, если есть оное — удалить его! 👌
Делается это просто:
- сначала переходим в параметры ОС (Win+i) и открываем вкладку «Обновление и безопасность / Центр обновления Windows / Просмотр журнала обновлений». См. стрелку-3 на скрине ниже; 👇
Просмотр журнала обновлений
- далее кликаем по пункту «Удалить обновления»;
Удалить обновления
- открывшейся список лучше отсортировать по дате установки. В моем случае «проблемное» обновление установлено 14 марта. Осталось только кликнуть по нему правой кнопкой мыши и удалить… Разумеется, ПК после этого нужно перезагрузить!
Список обновлений по дате
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Кстати, автоматически удалить эти некорректные обновления можно в 👉 командной строке (запущенной с правами админа). Что нужно вводить (выделено зеленым):
- wusa /uninstall /kb:5000802 (после каждой команды нужно нажать Enter)
- wusa /uninstall /kb:5000808
- wusa /uninstall /kb:5000822
- wusa /uninstall /kb:5000809
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👉 Microsoft также выпустила доп. обновления (для исправления проблемы «APC_INDEX_MISMATCH», возникающей при печати):
- Windows 10 версии 2004 и 20H2 — KB5001567;
- Windows 10 версии 1909 и Windows Server 1909 — KB5001566;
- Windows 10 версии 1809 и Windows Server 2019 — KB5001568;
- Windows 10 версии 1803 — KB5001565.
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ШАГ 2
Если накануне ваш ПК работал стабильно (а теперь внезапно стали появл. ошибки, синие экраны и пр.) — есть также смысл попробовать откатить систему (т.е. вернуть ее к заведомо исправному состоянию). Примечание: во многих версиях ОС Windows точки восстановления вкл. автоматически (даже, если вы вручную не настраивали их).
👉 Как их найти: нажать сочетание Win+R, в появившееся окно «Выполнить» ввести команду rstrui и нажать Enter. После нажать по кнопке «далее». 👇
Восстановление системных файлов и параметров
Если точки восстановления есть — здесь вы увидите их список. Ориентируйтесь по дате создания точки — нужно выбрать ту из них, когда компьютер работал корректно.
Примечание: дальнейший процесс восстановления проходит в автоматическом режиме. Пользовательские файлы и документы подобное восстановление не должно затрагивать (однако, драйверы, программы, ряд настроек — «затронуть» может).
Восстановление ПК до предыдущего состояния
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ШАГ 3
В рамках этой заметки нельзя не отметить, что причиной возникновения ошибки «APC_INDEX_MISMATCH» (помимо обновлений) часто явл. драйвера.
👉 В первую очередь я бы рекомендовал обратить внимание на:
- драйвера на принтер (сканер, МФУ и пр. сходные устройства). Кстати, у компании Kyocera есть универсальный драйвер Kyocera Classic Universal Printer Driver v.3.3 (3.3) 👇 — во многих случаях помогает решить проблему с невозможностью печати документов! Проверьте, возможно ваш производитель тоже выпустил различные дополнения под текущую Windows 10;
- драйвера на аудио- и видеокарту. В помощь: 👉 как обновить драйвер видеокарты (с удалением старого драйвера); рабочую и неоднократно проверенную версию 👉 Realtek HD можно найти тут;
- драйвера на мат. плату. В помощь: 👉 как узнать модель моей мат. платы.
Выбираем драйвер для принтера
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👉 Также в помощь!
Автоматически обновить драйвера для всего оборудования можно с помощью спец. утилит. При наличии проблем с появл. «синих экранов» — я бы порекомендовал попробовать прогнать систему ими (возможно, до-загрузят необходимый компонент…)
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👉 Кстати, можно также попробовать «выбрать» универсальный драйвер / либо драйвер другой версии, если он есть в системе (для аудио-, видеокарты).
Для этого зайдите в диспетчер устройств, кликните ПКМ по устройству и запустите обновление драйвера — далее укажите функцию, что вы хотите выбрать доступный драйвер самостоятельно (с этого ПК). См. пример ниже. 👇
Выбор текущего драйвера из списка установленных — диспетчер устройств
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ШАГ 4
Текущая рассматриваемая проблема может быть вызвана некорректной работой ОЗУ (из-за «разгона»). Речь идет о так называемых XMP профилях (когда, например, частота плашек ОЗУ DDR 4 поднимается с 2400 Mhz до 3200 Mhz).
Примечание: посмотреть частоту работы ОЗУ в Windows 10 можно в диспетчере задач (Ctrl+Alt+Del), вкладка «Производительность / Память».
Диспетчер задач — память / Windows 10
Чтобы исключить подобную причину — я бы порекомендовал 👉 в BIOS выставить частоту плашек ОЗУ в режим Auto 👇 (либо просто 👉 сбросить настройки BIOS в дефолтные).
ASRock UEFI — загружаем XMP профиль
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👉 В помощь!
Про XMP профили и разгон оперативной памяти — см. инструкцию
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ШАГ 5
На время диагностики я бы еще порекомендовал отключить виртуализацию (👉 что это). Узнать о том, включена ли она у вас — можно также в диспетчере задач (вкладка «Производительность / ЦП» 👇).
Виртуализация — отключено!
Для отключения виртуализации понадобиться 👉 зайти в BIOS и найти вкладку «Advanced»* — и перевести «…Virtualization Technology» в режим выкл./Disabled (* в зависимости от версии BIOS меню может быть несколько отличным).
Примечание: виртуализация может помечаться как «Virtualization Technology», «Intel Virtualization Technology», «AMD-V», «Intel VT-X» и пр. производными).
Intel Virtualization Technology — Disabled (выключено!)
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👉 В помощь!
Как включить (выкл.) виртуализацию (или почему тормозят и не работают виртуальные машины и эмуляторы, BlueStacks, например)
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ШАГ 6
Если все вышеприведенные шаги не принесли результата — пока лишь могу посоветовать «пробежаться» по общим рекомендациям при возникновении «синего» экрана. Ссылку на такую инструкцию привожу ниже. 👇
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👉 В помощь!
Синий экран в Windows 10: «На вашем ПК возникла проблема…» (а за ним перезагрузка компьютера) — см. пошаговую инструкцию + примеры диагностики
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Если вы устранили проблему иначе — подскажите решение в комментариях (заранее благодарю!).
Успехов!
👋
APC_INDEX_MISMATCH error mostly occurs when communication between the driver and the OS is asynchronous. This freezes the system and displays a Blue Screen of Death error.
Usually, a faulty update from Microsoft or a corrupted driver could result in this stop code error. So, to fix this, you can reinstall the .NET framework, and update/roll back Windows, or its drivers.
In some cases, simply updating the driver might not work and you might need to reinstall the entire driver.
Reinstall .NET Framework
The .NET framework builds and runs numerous Windows applications and services. Sometimes, Windows updates can mess with its pre-installed .NET Framework.
In such cases, you need to re-install the framework from Windows Feature in the control panel.
- Hit the Windows and R keys simultaneously. Here, type
appwiz.cpland then press Enter. - In the Program and Feature Window, click on Turn Windows features on or off.
- Here, uncheck .NET Framework 3.5 and .NET Framework 4.8. (versions might be different)
- Click on OK, and wait for the Operating System to apply changes.
- Click on Close, then restart the PC.
- Again, open Programs and Features > Turn Windows features on or off.
- If you cannot find this option, you need to enable it from the Group Policy Editor.
- Check .NET Framework 3.5 and .NET Framework 4.8 and click on OK.
- Select Let Windows Update download the files for you. Now, wait for the OS to download the necessary files.
- Finally, restart the PC.
Update Windows
Sometimes Microsoft may push an update that’s faulty. This might cause errors and bugs rather than fix them. And according to most users on the web, the error primarily occurred after a Windows update.
This was particularly the case when Microsoft rolled out the updates KB5000808 and KB5000802 for Windows 10 and KB5013943 for Windows 11. They also fixed both of these errors on their next Windows update.
But, if you are still using any of these older versions of Windows, I suggest that you update the OS immediately. For that,
- Press the Windows + I key.
- Once Setting opens, head over to Windows update (Update & Security > Windows Update for Windows 10)
- Click on Check for update, Install updates, or Install all.
- Restart your PC once the download completes.
Update Faulty Drivers
According to Microsoft’s official documentation, the error APC INDEX MISMATCH indicates a mismatch in the Asynchronous Procedure Calls (APC) state index. APC is a special function that executes asynchronously.
Driver files could have a mismatched number of calls to disable and re-enable APCs, resulting in a BSOD.
Several users also reported that the issue was due to Wi-Fi, Realtek’s sound, or printer driver. To ensure that it is not a driver’s fault, it is best that you keep all your drivers up-to-date
You can check your device manufacturer’s official website to check for any driver updates.
- Download the update from your device manufacturer’s website.
- Install the driver by running the executable file. You might have to extract the downloaded file first.
- Restart your PC.
Alternatively, you can also use the other driver available on your PC.
- Press Windows + X and click on Device Manager.
- Expand the troublesome hardware device.
- Double-click the device that requires an update.
- Go to the Driver tab and select Update Driver.
- Click on Browse my computer for drivers.
- Click on Let me pick from a list of available drivers on my computer.
- Check Show compatible hardware.
- Double-click the relevant driver from the list.
- Restart your PC.
Revert Windows Update
Microsoft could push a faulty update that could result in a blue screen. If you get the error after updating Windows, and there is no other latest version to update to.
In this situation, you can check if reverting the update works.
- Open Settings and head over to Windows update.
- Go to Update History.
- Scroll down to Uninstall updates.
- Here, search the recent Windows update and click on Uninstall.
If you cannot uninstall Windows updates due to BSOD, you can try booting to safe mode. Here, you can uninstall the updates.
Once uninstalled, Windows may again install updates automatically. So, I recommend turning off automatic Windows updates.
Roll-Back Driver Update
In case the issue started after a driver’s update, you will need to revert the driver update. You can either restore Windows or simply roll back driver updates from Device Manager.
- Select a driver from Device Manager.
- Go to the Driver tab.
- Select Roll Back Driver.
- Check any reason for the rollback and select Yes.
- Restart your PC.
Note: If you still get the blue screen error, check the crash dump files or the Windows event log. These will have heaps of information regarding the crash. You can use this information to determine what caused the issue and fix it.
The dreaded Blue Screen of Death (BSOD) is a sight no computer user wants to see. It signifies a critical error that has occurred in the system, causing it to crash and display a blue screen with an error message. One such error is the APC_INDEX_MISMATCH, which can be frustrating and confusing for users. In this article, we will explore what APC_INDEX_MISMATCH is, its causes, and how to fix it.
Understanding APC_INDEX_MISMATCH
APC_INDEX_MISMATCH is a Windows operating system error that typically occurs when there is a mismatch in the index of an Asynchronous Procedure Call (APC). APC is a mechanism used by Windows to execute code asynchronously in a separate thread. When the index of an APC does not match the expected value, it can lead to system instability and crashes.
This error is commonly associated with the file “ntoskrnl.exe,” which is a core component of the Windows operating system. It is responsible for various system functions, including process and memory management. When a problem occurs in this file, it can trigger the APC_INDEX_MISMATCH error.
Causes of APC_INDEX_MISMATCH
Several factors can contribute to the occurrence of the APC_INDEX_MISMATCH error. Understanding these causes can help in diagnosing and resolving the issue:
- Outdated or incompatible device drivers: Device drivers are essential software components that allow hardware devices to communicate with the operating system. If a driver is outdated or incompatible, it can lead to conflicts and trigger the APC_INDEX_MISMATCH error.
- Memory issues: Faulty RAM modules or incorrect memory configurations can cause various system errors, including APC_INDEX_MISMATCH. It is important to ensure that the computer’s memory is functioning correctly.
- Software conflicts: Conflicts between different software applications or incompatible software versions can lead to system errors. It is crucial to keep software up to date and resolve any conflicts that may arise.
- Malware or virus infections: Malicious software can disrupt system processes and cause errors, including APC_INDEX_MISMATCH. Regularly scanning for viruses and malware is essential to maintain system security.
How to Fix APC_INDEX_MISMATCH
Resolving the APC_INDEX_MISMATCH error requires a systematic approach. Here are some steps you can take to fix the issue:
1. Run the DISM and SFC scans
DISM (Deployment Image Servicing and Management) and SFC (System File Checker) are built-in Windows tools that can repair corrupted or missing system files and restore the health of your computer. Both DISM and SFC scans can be run from an elevated command prompt (with administrative privileges). Here are the steps to do so:
- To open the Command Prompt as an administrator in Windows, type “cmd” in the search bar and then right-click on the Command Prompt result and select “Run as administrator” as shown in the image below.
- To run a DISM scan, type the following command and press Enter:
dism /online /cleanup-image /restorehealth
This will check your Windows component store for corruption and automatically fix any problems it finds. This process may take several minutes or longer depending on your system
- To run an SFC scan, type in the Command Prompt the following command and press Enter:
sfc /scannow
This will scan all protected system files and replace any corrupted or missing ones with a cached copy. Wait for the scan to complete. It may take some time depending on your system configuration.
- After both scans are completed, you should restart your computer to apply any changes. Check to see if the issue is solved.
2. Check for faulty software.
If there is a specific program that is causing this issue, try uninstalling and then reinstalling it (eg. Microsoft DirectX, Microsoft Visual C++ Redistributable, NET Framework) to check if it will solve the problem.
Windows 11Windows 10Windows 8Windows 7
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First, open Windows Settings by pressing Windows+I on your keyboard. You can also right-click your Start button and select “Settings” from the list.
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When Settings opens, click “Apps” in the sidebar, then select “Apps & Features”.
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In Apps & Features settings, scroll down to the app list and search for the program you want to uninstall. When you find the program, click the three dots button beside it and select “Uninstall” in the menu that appears.
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In the next message box, confirm the uninstall process by clicking on Uninstall, then follow the prompts to uninstall the program.
- Press the Windows key + I on your keyboard to open the Settings app. You can also ope the Settings app by clicking the Start button on the taskbar, then select “Settings” (gear icon).
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When the “Windows Settings” window opens, click on “Apps“. By default, it should open “Apps and Features” but if it doesn’t, select it from the list on the left.
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In Apps & Features settings, scroll down to the app list and search for the program you want to uninstall. When you find the program, click on it and select “Uninstall” in the menu that appears.
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In the next message box, confirm the uninstall process by clicking on Uninstall, then follow the prompts to uninstall the program.
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Right-click on the Start button in the taskbar, then select “Programs and Features”. This will take you directly to your list of installed programs.
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The “Programs and Features” screen will be displayed with a list of all the programs installed on your computer. Scroll through the list until you find the program, then click to highlight it, then click the “Uninstall” button.
- In the next message box, confirm the uninstall process by clicking on Yes, then follow the prompts to uninstall program.
3. Scan for your computer for malware
Malware can damage your system files and registry entries and cause various errors. We will now, download and run a scan with Malwarebytes to check if you’re device is clean.
Malwarebytes is one of the most popular and most used anti-malware software for Windows, and for good reasons. It is able to destroy many types of malware that other software tends to miss, without costing you absolutely nothing. When it comes to cleaning up an infected device, Malwarebytes has always been free and we recommend it as an essential tool in the fight against malware.
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You can download Malwarebytes by clicking the link below.
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When Malwarebytes has finished downloading, double-click on the MBSetup file to install Malwarebytes on your computer. In most cases, downloaded files are saved to the Downloads folder.
You may be presented with a User Account Control pop-up asking if you want to allow Malwarebytes to make changes to your device. If this happens, you should click “Yes” to continue with the Malwarebytes installation.
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When the Malwarebytes installation begins, you will see the Malwarebytes setup wizard which will guide you through the installation process. The Malwarebytes installer will first ask you what type of computer are you installing this program on, click either Personal Computer or Work Computer.
On the next screen, click “Install” to install Malwarebytes on your computer.
When your Malwarebytes installation completes, the program opens the Welcome to Malwarebytes screen.
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Malwarebytes is now installed on your computer, to start a scan click on the “Scan” button. Malwarebytes will automatically update the antivirus database and start scanning your computer for malicious programs.
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Malwarebytes will now scan your computer for browser hijackers and other malicious programs. This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
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When the Malwarebytes scan is finished scanning it will show a screen that displays any malware, adware, or potentially unwanted programs that it has detected. To remove the malicious programs that Malwarebytes has found, click on the “Quarantine” button.
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Malwarebytes will now remove all the malicious files and registry keys that it has found. To complete the malware removal process, Malwarebytes may ask you to restart your computer.
4. Check for updates
Make sure your operating system, drivers, and other software are up to date. If the errors started happening after an update, you can uninstall that specific update patch.
To check for Windows updates, follow the below steps:
- Press the Windows key + I to open the Settings menu. Click the “Windows Update” tab on the left side of the screen.
For Windows 10 users, the Windows Update menu can be found in Settings > Update & Security > Windows Update. - Click the “Check for updates” button. This will initiate a scan for updates. If any updates are available, they will be downloaded and installed automatically.
- If you want to check for updates for other software, you can do so by opening the software and looking for a “Check for updates” option in the menu. You can also check the software’s website for updates.
5. Disable any unnecessary startup programs
Startup programs are applications that automatically launch when you start your computer. While some of these programs may be necessary for your system to function properly, others may be unnecessary and can cause errors.
- Open the Task Manager by pressing the Ctrl + Shift + Esc keys on your keyboard simultaneously.
- In the Task Manager, go to the “Startup” tab and disable any programs that you do not need to start automatically when you turn on your computer.
Keep in mind that some startup programs may be essential to the functioning of your system, so be careful not to disable any important programs.
6. Run a memory test
A faulty RAM module can cause random crashes. Run a memory test to check for any issues with your RAM. To run a memory test, follow these steps:
- Press the Windows key + R to open the Run dialog.
- Type “mdsched.exe” into the Run dialog and press Enter. This will launch the Windows Memory Diagnostic tool.
- You will be asked whether you want to restart your PC and run the test immediately or schedule the test to run the next time you start your PC. Choose the option you prefer and click “OK”.
If you choose to run the test immediately, your PC will restart and the test will begin. The test will run automatically and may take several minutes to complete.
- If the test finds any errors, it will display a message indicating the type and location of the error. You may need to replace your RAM if the test finds any errors.
- If the test completes without finding any errors, it will display a message indicating that the test has completed successfully.
7.Check your hardware
Start by inspecting your computer’s hardware components for any signs of damage or failure. Ensure that all connections are secure and that there are no loose cables. If you suspect a faulty component, consider consulting a professional or replacing it if necessary.
Next, check your RAM, hard drive, graphics card, and any other hardware components using the Windows Device Manager.
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To access the Device Manager, type “devmgmt.msc” into the search bar on the Start menu and select “Device Manager” from the list of results.
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In the Device Manager, you can view a list of all the hardware devices connected to your computer and check for any errors or issues. If you see a yellow exclamation point next to a device, it may indicate a problem with that device. You can right-click on the device and select “Update driver” or “Troubleshoot” to try and fix any issues.
8. Try a system restore.
If you have a restore point saved, you can try using it to revert your system to a previous state. This may fix the issue if it was caused by a recent change. To do a system restore follow these steps:
- Press the Windows key + S to open the Search menu.
- Type “system restore” into the search bar and click the “Create a restore point” result.
- Click the “System Restore” button.
- In the System Restore window, click “Next.”
- Select a restore point from the list and click “Next.” A restore point is a saved state of your system that you can use to revert your system to a previous state. Make sure to select a restore point that was created before you started experiencing problems.
- Click “Finish” to begin the restore process. Your PC will restart and the restore process will begin. This may take several minutes to complete.
- When the restore is complete, your PC will restart again. You may need to adjust your settings and reinstall any software that was installed after the restore point was created.
9. Reset your PC
One of the most drastic solutions is to reset your PC to its default configuration. This can be considered the nuclear option for fixing errors because it will wipe out all the third-party software you installed on your computer. However, this option can also be effective if none of the other methods work for you.
Before you reset your PC, make sure you back up your important data and files. You can also choose to keep your personal files in the Reset this PC tool, but it is better to have a separate backup just in case something goes wrong.
To reset your PC, follow these steps:
- Open Settings by pressing Windows + I keys.
- Click on System and then on Recovery.
- Under Reset this PC section, click on Reset PC button.
- Choose whether you want to keep your files or remove everything.
- Follow the on-screen instructions to complete the process.
After resetting your PC, you should be able to run your applications without getting any errors. However, keep in mind that this solution will also remove any custom settings and preferences you had on your computer. You will need to reinstall and configure your programs again after resetting.
Summary
APC_INDEX_MISMATCH is a Windows operating system error that occurs when there is a mismatch in the index of an Asynchronous Procedure Call (APC). Outdated or incompatible device drivers, memory issues, software conflicts, and malware infections can contribute to this error. To fix APC_INDEX_MISMATCH, it is important to update device drivers, check memory, resolve software conflicts, and scan for malware. By following these steps, users can resolve the issue and prevent future occurrences of the APC_INDEX_MISMATCH error.
Here are 10 basic security tips to help you avoid malware and protect your device:
To avoid potential dangers on the internet, it’s important to follow these 10 basic safety rules. By doing so, you can protect yourself from many of the unpleasant surprises that can arise when using the web.