Windows repeatedly displays Preparing Automatic Repair, Diagnosing your PC, or Automatic Repair couldn't repair your PC after an update, System Restore, driver change, registry modification, or interrupted recovery operation.

Automatic Repair and SrtTrail.txt do not have one dedicated error code. Search the exact screen text—Preparing Automatic Repair, Diagnosing your PC, Automatic Repair couldn't repair your PC—plus the displayed code, stop name, file, or the line copied from SrtTrail.txt.

Common codes that can lead into this loop include.

Also search the complete log reference, commonly \Windows\System32\LogFiles\Srt\SrtTrail.txt. The phrase Root cause found or a named boot critical file is more diagnostic than the fact that Automatic Repair looped.

Use this procedure as a decision path when the loop began after a recent Windows or software change and the system drive remains consistently visible and readable.

Do not use it as a generic collection of commands when firmware cannot see the drive, storage diagnostics fail, or the loop follows a confirmed hardware fault.

The exact Windows build may remain unknown during initial recovery. The immediately preceding change, Startup Repair result, and any named file or cause in the repair log should be established when possible.

Related cases:

  • Recover Windows after a specific update causes a boot failure
  • Recover boot after update error 0x800F0845 by rolling back the failing package
  • Use System Restore when Windows hangs indefinitely on the startup spinner

Before you start:

  • Windows Recovery Environment
  • Access to Advanced options
  • Command Prompt only for log inspection; the initial recovery steps use supported WinRE tools

At the Automatic Repair screen, select Advanced options > Troubleshoot > Advanced options. If Windows never exposes Advanced options, start matching Windows installation media and select Repair your computer.

  • Do not delete SrtTrail.txt; it is a log, not the cause.
  • Do not disable Automatic Repair as a permanent “fix.”
  • Do not run bootrec, CHKDSK, SFC, DISM, and registry restoration indiscriminately in one sequence.
  • Do not copy empty or unrelated RegBack files over active registry hives.
  • Do not reset or reinstall Windows before the narrower recovery branches have been evaluated.

Stop if the disk is intermittent, the log identifies a registry or file version that cannot be matched safely, or every supported rollback option fails.

Check the cause

  1. Select Startup Repair and allow one complete attempt.

  2. If Startup Repair reports that it could not repair the PC, return to Advanced options. Do not run it repeatedly without new evidence.

  3. Open Command Prompt.

  4. Display the Startup Repair log from the already-identified Windows volume W::

    type W:\Windows\System32\LogFiles\Srt\SrtTrail.txt | more

  5. Record:

    • Last successful boot time
    • Number of repair attempts
    • Any named root cause
    • Any named file, driver, disk, or registry hive
    • Whether Startup Repair says it performed a repair

  6. Treat the log as a lead, not proof. Match it to one of the branches below.

Follow only the branch supported by the timing or evidence.

Branch A — Loop began immediately after a quality update

  1. Return to Advanced options.
  2. Select Uninstall Updates.
  3. Select Uninstall latest quality update.
  4. Allow the operation to complete without forcing a shutdown.
  5. Restart and test Windows.

Branch B — Loop began during or after a feature-version upgrade

  1. Return to Uninstall Updates.
  2. If Uninstall latest feature update is offered, select it.
  3. Complete the rollback and restart.
  4. If the option is unavailable, do not substitute random package-removal commands. Move to System Restore or the logged driver branch.

Branch C — A usable restore point predates the problem

  1. Select System Restore.
  2. Choose the most recent restore point created before the triggering change.
  3. Review the affected programs before confirming.
  4. Complete the restore and restart.

Branch D — A specific recently installed driver is implicated

  1. Select Startup Settings > Restart.
  2. Choose Safe Mode.
  3. If Safe Mode starts, open Device Manager.
  4. Locate only the implicated device.
  5. Use Properties > Driver > Roll Back Driver when available.
  6. If rollback is unavailable and the driver is nonessential, uninstall that device without selecting permanent driver-package removal on the first attempt.
  7. Restart normally.

Branch E — SrtTrail identifies BCD or EFI boot files

Use FIX-003 or FIX-004 after independently confirming the partition and BCD condition. Do not rebuild BCD solely because Startup Repair failed.

Branch F — SrtTrail, CHKDSK history, or behavior indicates storage errors

Stop automated repair attempts. Check firmware visibility and storage health using FIX-005. Preserve data before a write-heavy file-system repair.

Branch G — No cause is isolated

  1. Try Safe Mode through Startup Settings.
  2. If Safe Mode starts, perform a clean boot:
    • Run msconfig.
    • On Services, select Hide all Microsoft services.
    • Disable the remaining third-party services.
    • Disable startup applications through Task Manager.
  3. Restart normally.
  4. Re-enable items in groups until the loop returns.

Check the result

  • Windows starts normally three times.

  • Startup Repair no longer launches automatically.

  • Event Viewer does not show the same boot-critical failure on each start.

  • The triggering driver, update, or service remains removed, rolled back, or corrected.

  • Sleep/wake and a cold boot both succeed.

  • Windows starts after uninstalling an update: The update or its interaction with a driver is the leading cause. Do not immediately reinstall it without reviewing the failure.

  • System Restore succeeds: Verify several boots before declaring resolution.

  • Safe Mode works but normal mode fails: A nonessential driver, service, or startup component is more likely than BCD damage.

  • Neither Windows nor matching recovery media can read the disk reliably: Stop and investigate storage hardware.

  • SrtTrail names no root cause: Do not treat the log filename itself as the error.

To undo the change:

Use System Restore to reverse driver or service changes made during troubleshooting. Re-enable clean-boot services and startup entries in the same recorded groups if they prove unrelated. An uninstalled update can be reoffered later after the underlying compatibility issue is understood.