First try to enter safe mode and uninstall the latest updates, which can solve most "uninstall changes" loop problems; 2. Enter automatic repair by force shutting down 3 times, select the advanced startup option, press F4 or F5 to enter safe mode with network after restart; 3. Open the settings or control panel in safe mode, find the recently installed KB update (such as KB503xxxx), and uninstall one by one; 4. If the system is normal after restart, run the Windows update troubleshooting tool to automatically repair the problem; 5. Run the command prompt as an administrator, execute DISM /Online /Cleanup-Image /RestoreHealth and sfc /scannow to repair the system files; 6. Make sure that the C drive has more than 10-20GB of free space, use the disk to clean and delete temporary files and update cache; 7. If the update still fails, stop Windows Update related services and rename SoftwareDistribution and catroot2 folders to reset the update components; 8. When all methods are invalid, use the Windows installation USB disk to boot, choose to repair the computer or perform in-place upgrade and reinstall the system without losing files; to prevent problems, avoid forced shutdown, maintain sufficient disk space, temporarily shut down third-party antivirus software, and execute system maintenance commands regularly, which can effectively solve and avoid the update failure cycle problem.

If you're seeing the error "We couldn't complete the updates. Undoing changes." on Windows — especially after a restart or during a Windows Update — it means the system tried to install updates but encountered a problem, so it's rolling back to the previous state to avoid instability.

This is frustrating, but it's usually fixed. Here's what's likely happening and how to resolve it.

? Why This Happens

Windows shows this message when:

• An update fails to install correctly (eg, due to corrupted files, driver conflicts, or interrupted downloads).
• The system reboots mid-update and can't finalize changes.
• There's not enough disk space.
• Critical system files are damaged.
• Third-party software (like antivirus) interferes.

? How to Fix It

Try these steps in order until the issue is resolved.

1. Wait and Let Windows Finish

Sometimes, Windows gets stuck in a loop, but it may resolve itself after a few cycles.
?? Leave it alone for a few hours. If it keeps failing after 3–4 attempts, proceed below.

2. Boot into Safe Mode and Uninstall Recent Updates

If Windows boots but loops on the update screen:

1. Force shut down the PC 3 times during startup to trigger Automatic Repair .
2. Go to Advanced Startup Options > Troubleshoot > Advanced Options > Startup Settings > Restart .
3. Press F4 or 5 to boot into Safe Mode with Networking .
4. Once in Safe Mode:
   • Open Settings > Apps > Apps & features > Manage optional features (or go to Control Panel > Programs > View installed updates ).
   • Look for recent KB updates (eg, KB503xxxx).
   • Uninstall the most recent ones.
5. Restart normally.

This often breaks the loop.

3. Run Windows Update Troubleshooter

• From Safe Mode or a working session:
  • Go to Settings > System > Troubleshoot > Other troubleshooters .
  • Run the Windows Update troubleshooter.

It can detect and fix common update issues automatically.

4. Run DISM and SFC

These repair system files:

Open Command Prompt as Administrator (via Safe Mode or recovery):

 DISM /Online /Cleanup-Image /RestoreHealth

Wait for it to finish (may take 10–20 mins).

Then run:

 sfc /scannow

Restart after completion.

? If DISM fails (eg, "source not found"), you may need a Windows installation USB to provide repair sources.

5. Free Up Disk Space

Windows needs at least 10–20GB free space to install updates.

• Delete temp files:
  Press Win R , type %temp% , delete everything.
• Use Disk Cleanup : Right-click C: drive > Properties > Disk Cleanup > Clean up system files (include "Windows Update Cleanup").

6. Reset Windows Update Components

If updates keep failing:

In Command Prompt (Admin), run:

 net stop wuauserv
net stop cryptSvc
net stop bits
net stop msserver

Then:

 ren C:we couldnt complete the updates undoing changes win errorWindowswe couldnt complete the updates undoing changes win errorSoftwareDistribution SoftwareDistribution.old
ren C:we couldnt complete the updates undoing changes win errorWindowswe couldnt complete the updates undoing changes win errorSystem32we couldnt complete the updates undoing changes win errorcatroot2 catroot2.old

Restart the services:

 net start wuauserv
net start cryptSvc
net start bits
net start msserver

Now try checking for updates again.

7. Use Windows Installation Media (Last Resort)

If nothing works:

• Create a bootable USB using Microsoft's Media Creation Tool .
• Boot from it and choose Repair your computer .
• Use Startup Repair or System Image Recovery .
• Or perform an in-place upgrade : Install Windows over itself without losing files.

?? Pro Tips to Avoid This

• Don't force-shutdown during updates.
• Keep 20% of your drive free.
• Temporarily disable third-party antivirus during updates.
• Regularly run sfc /scannow and disk cleanup.

Basically, the “undoing changes” loop is Windows protecting itself — but with the right steps, you can fix it and get updates working again. Start with Safe Mode and uninstalling the last update — that solves most cases.

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