Windows 11 super slow after having installed an update

neptunium 11
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Hello everyone. I just stumbled upon this website and I thought I'd give it a try, because I haven't found any solution to my issue so far:
I use Windows 11 and approximately one month ago, it wanted to install an update, so I just proceeded with it. After the reboot, my computer became much slower, especially when using the File Explorer. I also have a NAS and when connecting to it, it does not answer anymore.

Unfortunately, I’m not the most technical person and I have no idea what to do. Any idea?

windows-11
1 Answers

The recent KB5063878 update has reportedly caused many issues. That may explain the issues you're having.

In case you haven't solved the problem in the meantime, here are some simple solutions you can try:

Microsoft has addressed several problems introduced by KB5063878 in later cumulative updates, most notably KB5065426 and anything released after it.

Steps:

  1. Go to Settings → Windows Update
  2. Click Check for updates
  3. Install KB5065426 or any newer cumulative update
  4. Restart the PC

This is the best option if your system is still usable, as it keeps security updates intact and resolves known regressions (e.g. streaming lag, app issues).

Option 2: Uninstall KB5063878

If your system became unstable immediately after installing KB5063878 and you can’t install a new update.

Steps:

  1. Settings → Windows Update → Update history
  2. Select Uninstall updates
  3. Find KB5063878 and uninstall it
  4. Restart the system
  5. (Optional) Pause updates temporarily to prevent reinstallation

This often restores stability but temporarily removes the security fixes included in that update.

b.s1
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Windows 11 super slow after having installed an update
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