Meta Description:
Fix APC_INDEX_MISMATCH BSOD error on Windows 10/11 with easy step-by-step solutions. Solve driver and system conflicts quickly.
What Is APC_INDEX_MISMATCH?
The APC_INDEX_MISMATCH is a Blue Screen of Death (BSOD) error that occurs when there is a mismatch in the Asynchronous Procedure Call (APC) state index.
In simple terms, Windows detects inconsistency in system processes, usually caused by drivers or system-level conflicts.
Symptoms
- Blue screen with APC_INDEX_MISMATCH code
- Crashes during startup or shutdown
- Errors when using webcam or audio apps
- Random freezes before crash
Main Causes
- Faulty or outdated drivers
- Audio driver issues (very common)
- Corrupted system files
- Windows update bugs
- Third-party software conflicts
How to Fix APC_INDEX_MISMATCH
Follow these step-by-step fixes:
1. Update Audio Drivers (Most Common Fix)
This error is often linked to audio drivers.
Steps:
- Press
Windows + X→ Device Manager - Expand Sound, video and game controllers
- Update all audio drivers
👉 Related article:
SYSTEM_THREAD_EXCEPTION_NOT_HANDLED Fix
2. Reinstall Display Drivers
Some cases are GPU-related.
Steps:
- Open Device Manager
- Uninstall Display adapter
- Restart your PC
👉 Related article:
VIDEO_TDR_FAILURE Fix
3. Run System File Checker
Open Command Prompt (Admin):
sfc /scannow
Then:
DISM /Online /Cleanup-Image /RestoreHealth
4. Disable Problematic Drivers (DisplayLink Fix)
If you use DisplayLink:
- Uninstall DisplayLink drivers
- Restart your PC
5. Update Windows
Go to:
Settings → Windows Update → Check for updates
6. Disable Fast Startup
Steps:
- Open Control Panel
- Power Options
- Choose what power buttons do
- Disable Fast Startup
7. Scan for Malware
Run a full system scan using Windows Security.
8. Uninstall Recently Installed Apps
Remove apps installed before the error appeared.
Advanced Fix
Reset Windows
If the issue persists:
- Go to Settings → Recovery
- Reset this PC
Prevention Tips
- Keep drivers updated
- Avoid incompatible software
- Install stable Windows updates
- Maintain system health
Conclusion
The APC_INDEX_MISMATCH error is usually caused by driver conflicts, especially audio drivers.
Start with:
- Updating audio drivers
- Running system scans
- Checking recent installations
These steps fix most cases effectively.