Fix Windows 11 Upgrade Stuck or Failing to Install

What Causes This?

A Windows 11 upgrade usually gets stuck or fails because something interrupts the setup process. Common causes include not enough free disk space, corrupted Windows Update files, outdated drivers, damaged system files, or security software blocking the installer. In some cases, background apps or disconnected update services leave the upgrade hanging partway through.

Common Symptoms

• The Windows 11 upgrade freezes at a certain percentage for a long time
• You see errors like “Installation failed” or “Undoing changes made to your computer”
• The PC restarts repeatedly during the upgrade
• Windows Update downloads the upgrade but never finishes installing
• Setup reports that your device is not ready even though it meets the requirements

How to Fix It Manually

1. Restart your PC and disconnect unnecessary devices

   • Save your work and restart Windows normally.
   • Unplug non-essential USB devices like external drives, printers, webcams, and dongles.
   • Leave only your keyboard, mouse, and internet connection active. Extra devices can cause driver conflicts during setup.

2. Make sure you have enough free space

   • Open File Explorer with Win + E.
   • Select This PC and check free space on your C: drive.
   • Try to keep at least 25–30 GB free before upgrading.
   • If space is low, open Settings > System > Storage > Temporary files, select items you do not need, and click Remove files.

3. Run Windows Update troubleshooter

   • Open Settings with Win + I.
   • Go to System > Troubleshoot > Other troubleshooters.
   • Find Windows Update and click Run.
   • Let Windows detect and repair common update problems, then restart your PC.

4. Repair system files

   • Click Start, type cmd, then choose Run as administrator for Command Prompt.
   • Run this command:

     sfc /scannow

   • After it finishes, run:

     DISM /Online /Cleanup-Image /RestoreHealth

   • Restart your PC after both scans complete. These tools fix corrupted system files that can break upgrades.

5. Reset the Windows Update cache

   • Open Command Prompt as administrator again.
   • Run these commands one at a time:

     net stop wuauserv
     net stop bits
     net stop cryptsvc
     ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
     ren C:\Windows\System32\catroot2 catroot2.old
     net start wuauserv
     net start bits
     net start cryptsvc

   • Restart your PC and try the upgrade again. This forces Windows to rebuild damaged update files.

6. Temporarily disable third-party antivirus and close background apps

   • Open Task Manager with Ctrl + Shift + Esc.
   • Under Processes, close non-essential apps, especially cleanup tools, RGB software, and third-party security programs.
   • If you use non-Microsoft antivirus, temporarily disable it before retrying the upgrade.
   • Do not uninstall security software unless the vendor specifically recommends it.

7. Try the Windows 11 Installation Assistant or ISO

   • Visit Microsoft’s official Windows 11 download page.
   • Use the Installation Assistant or mount the Windows 11 ISO and run setup.exe.
   • Choose the option to keep personal files and apps.
   • This often works when the built-in Windows Update process is stuck or corrupted.

Fix It Automatically with Kudu

Kudu can scan your PC for upgrade blockers like temporary file clutter, broken update leftovers, and system issues that interfere with Windows 11 setup. It gives you a faster way to clear space and remove common upgrade obstacles without digging through multiple Windows menus.

Download Kudu Free →