[Fix] 0x00000001 APC_INDEX_MISMATCH error in Windows 7

Microsoft has reported that some Windows 7 and Windows Server 2008 R2 can experience STOP 0x00000001 error, which is hexadecimal code for APC_INDEX_MISMATCH error, during startup or at other times.

Stop Error

The complete error looks something like this:

STOP: 0x00000001 (parameter1, parameter2, parameter3, parameter4)
APC_INDEX_MISMATCH

The parameters in this Stop error message may vary, depending on the configuration of the computer.

There are several reasons for the problem to occur, it can be due to hardware or software driver issues, it can be due to memory corruption, or it may be due to too much RAM that exceeds the capability of the BIOS and motherboard. If you have verified all options like re-installed drivers, software, used memory diagnosis etc, and still face this problem, then there is one more reason, it is due to issue with the Windows system file win32k.sys. Microsoft has released an hotfix to fix this issue. Simply download the hotfix, run it, and follow the on-screen instructions.


Download Hotfix

Applies to Windows 7, Windows 7 Service Pack 1 (SP1, Windows Server 2008 R2, and Windows Server 2008 R2 Service Pack 1 (SP1)
Did it fix your computer’s problem? Let us know in comments below.

Kiran Kumar

Hi there! Kiran Kumar is an Engineer by profession, and loves blogging primarily on Microsoft Windows operating system and also enjoys reviewing software and products. Currently, he is exploring Windows 10 and you will see a lot of articles on know-how about it. When he is not writing for TWP, he enjoys time with his Family, listens to lot of music, enjoys Biking, and occasionally plays racing games on Xbox One.