Preparing Automatic Repair. Diagnosing your PC. Attempting repairs. Then, maddeningly, back to Preparing Automatic Repair. This loop means Windows detected a startup problem, tried to fix it, failed, and — instead of telling you what went wrong — just tries again. On Acer laptops it is commonly triggered by a bad Windows update, a corrupted boot configuration, or a driver that breaks the boot chain.

The way out is to stop letting Automatic Repair run the show. Every fix below starts from the recovery menus that the loop itself gives you access to — you do not need installation media for most of them. Work in order, and give each fix a proper restart test before moving on.

Why this happens

  • A Windows update broke the boot chain: a feature or quality update that applied incorrectly leaves startup files in a mismatched state, and Automatic Repair cannot reconcile them.
  • Corrupted Boot Configuration Data: the BCD tells the bootloader where Windows lives. Damage here means every boot attempt fails identically, which is exactly what a loop looks like.
  • A faulty driver loading at boot: storage, chipset, or graphics drivers that crash during startup trigger the repair cycle on every attempt.
  • Disk errors in critical areas: bad sectors landing on boot files cause failures that Automatic Repair detects but cannot repair on its own.
  • Recent hardware or BIOS changes: a new SSD, changed SATA mode, or toggled Secure Boot can invalidate the boot path Windows expects.
  • The repair tool looping on itself: occasionally nothing is deeply broken — Automatic Repair just keeps re-running because its own state flag got stuck.

How to fix it

Work through these in order, from the quickest checks to the deeper repairs. Most people are back up and running by Fix 4 or 5.

Fix 1: Force your way to Advanced options

The loop usually offers an Advanced options button after a failed repair — but if yours just reboots endlessly, force the menu open.

  1. Let the loop run until you see Automatic Repair couldn’t repair your PC, then click Advanced options. If you never see it, force-power-off at the Acer logo three times to trigger Automatic Repair manually.
  2. From here, every remaining fix starts at Troubleshoot > Advanced options. Bookmark this path mentally — you will use it repeatedly.
  3. Do not choose Continue (it just re-enters the loop) and do not choose Turn off your PC yet.
  4. If the screen instead shows a blue Recovery error with a code like 0xc000021a, note the code — but the fixes below still apply.

Fix 2: Run Startup Repair once, properly

Yes, it already ran — but the automatic attempt sometimes bails out early. A manual run from the menu occasionally succeeds where the auto-triggered one failed.

  1. Go to Troubleshoot > Advanced options > Startup Repair.
  2. Select your account, enter your password, and let it run to completion without touching anything.
  3. If it reports it could not repair, click Advanced options to return to the menu — do not restart into the loop.
  4. One failed manual run is enough information. Move on; repeating it changes nothing.

Fix 3: Rebuild the BCD and boot records

This is the fix that breaks most Acer repair loops. It rewrites the boot files that Automatic Repair is choking on.

  1. Open Troubleshoot > Advanced options > Command Prompt.
  2. Run bootrec /fixmbr, then bootrec /fixboot, then bootrec /rebuildbcd, pressing Enter after each.
  3. If fixboot returns Access is denied, run diskpart, list vol, find the FAT32 EFI partition, select vol N, assign letter=S:, exit, then bcdboot C:\windows /s S: /f UEFI.
  4. Answer Y if rebuildbcd asks to add the installation. Type exit and choose Continue to restart.
  5. If Windows boots, immediately run Settings > Windows Update and install everything — a half-applied update often caused this.

Fix 4: Disable the automatic repair loop flag

Windows sets a flag telling itself to launch repair on next boot. Clearing it stops the self-perpetuating cycle and lets you see the real error, if any.

  1. In the recovery command prompt, run bcdedit /set {default} recoveryenabled No.
  2. Also run bcdedit /set {default} bootstatuspolicy ignoreallfailures to stop Windows treating every hiccup as a repair trigger.
  3. Type exit and Continue. Windows will now try a straight boot.
  4. If it boots, the loop is broken — update drivers and run sfc /scannow from an elevated prompt to address whatever originally tripped the repair.
  5. If it now shows a specific blue screen instead of looping, troubleshoot that stop code directly — the blue screen of death guide picks up from here.

Fix 5: Uninstall the most recent update

When the loop started the morning after an update, the update is guilty until proven innocent. Remove it from recovery.

  1. Go to Troubleshoot > Advanced options > Uninstall Updates.
  2. Choose Uninstall latest quality update first and restart to test.
  3. Still looping? Return and choose Uninstall latest feature update — slower, but it rolls back the bigger changes.
  4. Once booting, pause updates for a week: Settings > Windows Update > Pause updates, and check Microsoft’s Windows support hub for known issues with the KB number you removed.
  5. Before unpausing, update the storage and chipset drivers manually so the update does not collide with old drivers again.

Fix 6: Check the disk for errors

Loops that survive boot rebuilds often have a disk problem underneath. Scan the drive before trying anything destructive.

  1. Open the recovery command prompt and run chkdsk C: /f /r.
  2. Let it finish completely — on a 512 GB SSD this is typically 20–60 minutes. Do not force-power-off mid-scan.
  3. Follow with sfc /scannow /offbootdir=C:\ /offwindir=C:\windows to repair system files.
  4. Restart via Continue. If chkdsk reported bad sectors, back up your data the moment Windows loads — recurring loops after this point to a failing drive.
  5. Acer’s hardware diagnostics (press F2 at boot for BIOS, or use the built-in diagnostics on the boot menu) can confirm drive health with a SMART check.

Fix 7: System Restore, then Reset as the last resort

When targeted repairs fail, roll back the whole system state — first surgically with System Restore, then with a full Reset.

  1. Go to Troubleshoot > Advanced options > System Restore and pick the newest restore point from before the looping started.
  2. If no restore points exist, go to Troubleshoot > Reset this PC > Keep my files.
  3. If Keep my files fails, the Windows image itself is damaged — choose Remove everything (back up via the command prompt with robocopy first if you can).
  4. After any reset, install drivers from Windows Update’s Optional updates before reinstalling Acer utilities one at a time.
  5. For machines that also struggle to reach recovery at all, this Safe Mode guide covers alternative ways into the repair environment.

Closing

The Automatic Repair loop is Windows trying to help and making things worse — but the recovery menu it traps you in contains everything needed to escape. Rebuild the boot files, clear the repair flag, and remove the offending update, in that order, and the vast majority of Acer laptops boot normally again. If the loop ever returns, the pattern will be familiar, and this time you will know exactly which fix to reach for first.

Frequently asked questions

How long should I let Automatic Repair run before giving up?
Give a single Startup Repair attempt up to an hour on a slow drive. But if the machine has already looped through Preparing Automatic Repair and Diagnosing your PC three or more times, you have your answer — it is not going to fix itself. Move to the manual repairs above instead of watching it loop overnight.
Will these fixes delete my files?
No. Bootrec, bcdedit, chkdsk, SFC, update uninstalls, and System Restore all preserve personal files — your documents, photos, and downloads are untouched. Only the Reset this PC with Remove everything option wipes data, and that is explicitly the last resort in Fix 7.
Why does the loop happen after every Windows update on my Acer?
Recurring post-update loops usually mean an old storage or chipset driver conflicts with the new Windows build. Update those drivers manually from Windows Update’s Optional updates section before the next Patch Tuesday, and the updates stop breaking the boot chain.
The loop mentions SrtTrail.txt. Is that a different problem?
It is the same family. SrtTrail.txt is the log file Automatic Repair writes when it fails, so a loop that names it just means the repair logged its failure. The bootrec and chkdsk fixes in this guide are exactly what that variant needs too.