Symptoms
- Screen says Preparing Automatic Repair
- PC restarts and repeats the same screen
- Never reaches the sign-in screen
- Sometimes shows Diagnosing your PC for a long time
Likely causes
- CommonCorrupted system files or boot configurationA bad shutdown, update, or malware can damage files Windows needs to start.
- CommonRecent Windows update didn't finish installingInterrupted or failed updates often trigger this loop.
- PossibleFailing hard drive or SSDA drive with bad sectors can prevent Windows from loading reliably.
- PossibleThird-party antivirus or disk software conflictSome security tools interfere with the boot process.
- Less commonLoose or failing data cable (desktops)A marginal SATA/power connection can look like a boot failure.
What to do
- Let the repair loop run through 2–3 cycles; sometimes it resolves itself on the next attempt.
- On the 'Automatic Repair' screen, choose Advanced options to reach the Windows Recovery Environment.
- Try Startup Repair first from Troubleshoot > Advanced options; it scans and fixes common startup problems automatically.
- If that fails, open Command Prompt from Advanced options and run 'chkdsk C: /f' followed by 'sfc /scannow' to check the disk and system files.
- If the PC still won't boot, try System Restore to a date before the problem started, if a restore point exists.
- As a last resort, use 'Reset this PC' with the 'Keep my files' option to reinstall Windows without losing personal files.
- If none of this works, back up files from Recovery Environment (if accessible) before a clean reinstall.
Tools and parts
- Bootable Windows recovery/installation USB drive
- Another working computer to create the USB
When to call a pro
If Startup Repair and Reset this PC both fail, or you hear clicking noises from the drive, take it to a professional to attempt data recovery before reinstalling anything.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.