Error codes

0x000000C9

DRIVER_VERIFIER_IOMANAGER_VIOLATION

What it means

Driver Verifier, a Windows tool that watches drivers closely, caught one breaking the rules. Disable Verifier after you read the report.

Common causes

• A driver being tested with Driver Verifier
• A third-party driver with a real bug

How to fix it

1. Turn Driver Verifier off for normal use: run verifier /reset in Terminal (Admin) and restart.
2. 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).
3. Uninstall or update the driver named in the crash dump.
4. 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.