If Windows 10 is stuck on “Diagnosing your PC” or “Preparing Automatic Repair,” give it 15–30 minutes first, because Automatic Repair can take a while. If it loops or never finishes, force a restart, then use Advanced options > Startup Repair. If that fails, boot into Safe Mode to uninstall a recent update or driver, run disk and system file checks from Command Prompt, or use System Restore. Reset this PC is the last resort.
Windows 10 reached end of support on October 14, 2025. Consumer Extended Security Updates (ESU) now run until October 12, 2027.
Quick Answer
Wait, then hold the power button to restart. On the recovery screen: Advanced options > Troubleshoot > Advanced options > Startup Repair.
Step 1: Restart and Try Startup Repair
- Unplug USB drives and other accessories.
- Hold the power button for 10 seconds, then turn the PC on.
- If the Automatic Repair screen appears, click Advanced options.
- Choose Troubleshoot > Advanced options > Startup Repair.
Step 2: Try These Fixes in Order
| Fix | How |
|---|---|
| Uninstall a recent update | Advanced options > Uninstall Updates |
| Safe Mode | Advanced options > Startup Settings > Restart > 4; then remove recent drivers or apps |
| Check the disk | Advanced options > Command Prompt > chkdsk C: /f (the drive letter may differ in recovery) |
| Repair system files | Command Prompt > sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows |
| System Restore | Advanced options > System Restore, pick a point before the problem |
| Reset this PC | Troubleshoot > Reset this PC > Keep my files |
Skip Automatic Repair Temporarily
If Automatic Repair keeps running and you need to reach Windows to fix the real cause, you can turn it off from the recovery Command Prompt (Advanced options > Command Prompt) with bcdedit /set {default} recoveryenabled no. Turn it back on afterward with bcdedit /set {default} recoveryenabled yes. This only stops the repair screen; it doesn’t fix the underlying problem, so continue with the steps above.
Common Causes
- A failed or interrupted update.
- A new driver or hardware change.
- File system errors or a failing drive.
- Power loss during startup.
If a driver caused the loop, see finding corrupt drivers.
Troubleshooting
- BitLocker recovery key requested: See finding your BitLocker recovery key.
- Stuck in Safe Mode after fixing: See getting out of Safe Mode.
- Drive not found: The drive may be failing. Back up data from another PC or recovery environment before resetting.
- Other ways into recovery: See opening Advanced startup options.
Frequently Asked Questions
How long should Diagnosing your PC take?
Usually a few minutes; sometimes up to 30. Longer, or repeated loops, need manual fixes.
Will Startup Repair delete my files?
No. Only Reset this PC with Remove everything erases files.
Summary
- Wait, then force restart.
- Run Startup Repair from Advanced options.
- Uninstall updates, use Safe Mode, or run chkdsk and sfc.
- Use System Restore or Reset this PC as a last resort.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.