Last updated on April 17th, 2021
The blue screen error "APC INDEX MISMATCH" in file "win32kfull.sys", may appear after installing the Cumulative Update for Windows 10 KB5000802. The BSOD error "APC INDEX MISMATCH" caused by win32kfull.sys and win32kbase.sys drivers, usually occurs when printing in Windows 10, but in many cases the problem occurs at system startup which makes the PC unusable.
This tutorial contains instructions on how to resolve the APC_INDEX_MISMATCH BSOD error caused by win32kfull.sys in Windows 10.
How to fix: APC_INDEX_MISMATCH in Windows 10.
To easy fix the "APC INDEX MISMATCH" BSOD error in Windows 10 follow the instructions below according your case:
Case A. If you can login to Windows 10.
If you can login to Windows 10, then you have the following methods to resolve the "APC INDEX MISMATCH" error.
Case B. If you cannot login to Windows 10.
If you cannot login to Windows 10, you have to fix the "APC INDEX MISMATCH" error, from the Windows Recovery Environment (WinRE)*, by using one of these methods:
* Note: If you can't sign in to Windows 10 but can get to the sign-in screen, hold down the SHIFT key, click the Power icon on the lower right corner and choose Restart. After restart, follow the steps in method-3 or Method-4 below to fix the "APC INDEX MISMATCH" BSOD.
To uninstall the KB5000802 Update, that cause the BSOD error "APC INDEX MISMATCH" in file "win32kfull.sys":
1. Go to Start > Settings > Update & Security > Windows Update.
2. Click View update history.
3. Select the Security Update for Microsoft Windows (KB5000802) and click Uninstall.
4. After uninstall reboot your PC.
An alternative method to fix the "APC INDEX MISMATCH" error in windows 10, is to download and install the Cumulative Update for Windows 10 (KB5001649) from Microsoft Update Catalog.
Normally, after the BSOD screen, your computer will restart automatically in the Recovery screen.
1. Click See advanced repair options.
2. Click Troubleshoot -> Advanced Options -> Uninstall Updates.
3. Click Uninstall latest quality update.
4. When the update is uninstalled login to Windows 10 normally.
5. Proceed to download and install KB5001649 update to avoid the "APC INDEX MISMATCH" error to appear again.
To restore your system to a previous working state:
1. At the Recovery screen, click See advanced repair options.
2. Click Troubleshoot -> Advanced Options -> System Restore.
3. After restart, select your account and type your password if you have. *
* Note: If you have more than one account on your computer, choose one with administrator privileges.
4. At the first screen of System Restore, click Next. *
* Note: If no Restore points has been created on you PC, then click Cancel and follow the instructions on Method-3 above to fix the problem.
5. Select a previous restore point and click Next.
6. At the next screen click Finish and the wait for the restoration process to complete.
7. After logging in to Windows proceed to download and install KB5001649 update to avoid the "APC INDEX MISMATCH" error to appear again.
That's it! Which method worked for you?
Let me know if this guide has helped you by leaving your comment about your experience. Please like and share this guide to help others.