Windows 10/11 Stuck on “Diagnosing Your PC” or “Preparing Automatic Repair”? Here’s How to Fix It

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by

Himanshu
in ,

Seeing “Diagnosing your PC” or “Preparing Automatic Repair” on a black screen when starting Windows 10 or 11 can be frustrating. This loop happens when Windows detects a startup problem but fails to fix it automatically.

Below is a detailed guide on why it happens and step-by-step fixes you can try at home.

🔎 Why This Happens

Common causes of being stuck on “Diagnosing your PC” or “Preparing Automatic Repair” include:

  • Corrupted system files (e.g. after improper shutdown or power failure).
  • Damaged boot sector or Master Boot Record (MBR).
  • Faulty or newly added hardware (RAM, HDD/SSD).
  • Outdated or conflicting drivers.
  • Windows updates that didn’t complete properly.
  • Malware or disk errors.

✅ Quick Fixes Before Advanced Steps

1️⃣ Hard Reboot

Hold the power button for 10 seconds to shut down. Disconnect all USB drives, external HDDs, printers, etc. Restart PC.

2️⃣ Boot Into Safe Mode

  • Turn PC on. As soon as Windows logo appears, press Power to force shutdown. Repeat 3 times — this forces Advanced Startup.
  • Select Troubleshoot > Advanced Options > Startup Settings > Restart > Press 4 (Enable Safe Mode).
    If you can log in Safe Mode, uninstall recently added software or drivers.

3️⃣ Run Startup Repair

  • In Advanced Startup (above), select Troubleshoot > Advanced Options > Startup Repair.
  • Let Windows try to repair boot issues.

🔧 Advanced Solutions

A. Run System File Checker (SFC) & DISM

  1. Boot into Advanced Startup > Command Prompt.
  2. Type: sfc /scannow
  3. Then run: DISM /Online /Cleanup-Image /RestoreHealth

B. Repair Boot Configuration

In Command Prompt:

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

Restart PC after each.

C. Check Disk for Errors

chkdsk C: /f /r

D. System Restore

  • Advanced Startup > Troubleshoot > Advanced Options > System Restore.
  • Choose a restore point created before the issue.

E. Uninstall Recent Updates

  • Advanced Startup > Troubleshoot > Advanced Options > Uninstall Updates.
  • Remove latest quality or feature update.

F. Reset This PC (Keep Files)

If nothing works:

  • Advanced Startup > Troubleshoot > Reset This PC > Keep my files.

📝 Quick Reference Table

SymptomFix
Loop on Diagnosing your PCHard reboot, disconnect peripherals
Safe Mode boots fineUninstall recent drivers/programs
Still stuckStartup Repair from Advanced Options
Corrupted filesSFC /scannow & DISM
Boot errorsbootrec commands to rebuild BCD
Disk errorschkdsk /f /r
Updates issueUninstall latest update
Nothing worksReset PC (keep files)

💡 Tips to Prevent Future Issues

  • Keep Windows & drivers updated.
  • Shut down properly; avoid forced power-offs.
  • Regularly back up data.
  • Use a UPS to prevent power-related corruption.

⚠️ Disclaimer

Some fixes involve Command Prompt and system settings. Proceed carefully; if unsure, seek professional help. Always back up important data first.