kb5066128 successfully installs but needs to be installed again etc...

Question

kb5066128 keeps reinstalling, says it was successful but keeps finding it again

Answer 1

Hi Sarah Simmons,

Thank you for reaching out to Microsoft Q&A forum. I understand how concerning it can be to see the same update install successfully and then appear again.

What you’re seeing with KB5066128 is something we do occasionally run into. In most cases, the update has actually installed, but Windows Update doesn’t fully clear its temporary detection files, so it keeps offering the update again.

To get this sorted, I recommend the steps below, starting with the simplest option:

Step 1: Quick check

Please restart your PC once more, then go to:

Settings > Windows Update > Update history

If KB5066128 shows as Successfully installed and no longer reappears, you’re all set.

Step 2: Run the Windows Update troubleshooter

If the update still comes back:

1. Open Settings
2. Go to System > Troubleshoot > Other troubleshooters
3. Select Windows Update and click Run
4. Restart your PC when it finishes, then check for updates again

This tool automatically fixes common update detection issues.

Step 3: Reset the Windows Update cache

If it’s still looping, resetting the update cache usually resolves it. This does not remove any installed updates or personal files.

1. Open Command Prompt as Administrator
2. Run the following commands one at a time:

net stop bits
net stop wuauserv
ren %systemroot%\softwaredistribution softwaredistribution.bak
ren %systemroot%\system32\catroot2 catroot2.bak
net start bits
net start wuauserv

Restart your PC and check Windows Update again

Step 4: Repair system files

If the update still appears after the cache reset, repairing system files can help:

1. Open Command Prompt as Administrator
2. Run:

      sfc /scannow
   

3. When that completes, run:

      DISM /Online /Cleanup-Image /RestoreHealth
   

4. Restart your PC and check for updates

After these steps, Windows Update should correctly recognize KB5066128 as installed and stop offering it again.

If you still see the update after trying this, please let me know. I’m happy to take a closer look and help you from there.

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Answer 2

KB5066128 is a cumulative .NET Framework update for Windows 11 25H2 that may require a restart if any affected files are in use. If Windows Update keeps offering the same update even though it reports as successfully installed, this typically indicates that Windows Update did not fully detect the installation or that the update did not complete correctly the first time.

Use the following steps:

1. Restart the device
   • Because this update requires a restart when affected files are in use, restart the PC once (or again) after the “successful” installation so Windows can finish applying the update.
2. Check update history
   • Open Settings → Windows Update → Update history.
   • Confirm whether KB5066128 shows as Successfully installed or Failed.
   • If it shows as Failed, let Windows try again later or manually trigger Check for updates.
3. If the same update keeps reappearing
   • This behavior matches the general case where Windows Update repeatedly offers the same update if it was not installed correctly or detection fails.
   • Allow Windows Update to retry installation later, then re-check Update history for any error codes.
   • If errors appear, search those error codes on Microsoft Support for targeted fixes.
4. If the issue persists
   • Collect logs as described in the Windows troubleshooting article and contact Microsoft Support for deeper analysis, especially if the update keeps looping despite showing as installed.

Note: Do not attempt to fix this by manually editing the registry, as this can cause further system issues.

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References:

• October 14, 2025-KB5066128 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11, version 25H2
• Windows Update or Microsoft Update repeatedly offers the same update