Error codes

0x00000121

DRIVER_VIOLATION

What it means

A driver broke a kernel rule that Windows checks on purpose, such as freeing memory it does not own or calling an API from the wrong context.

Common causes

• A driver written for a different Windows version
• Driver Verifier being enabled and catching the bug
• Two versions of the same driver fighting over one device

How to fix it

1. Open the crash dump in WhoCrashed or BlueScreenView: it usually names the driver file that caused it (for example nvlddmkm.sys is the NVIDIA driver).
2. Update the graphics, chipset and network drivers from the maker's site (NVIDIA, AMD, Intel or your board vendor), not from a driver-updater tool.
3. Turn Driver Verifier off again if you enabled it: run verifier /reset and restart.