How to fix WindowsAppRuntime.1.8 stuck on reserving space for the past hour

Try these in order:

1. Close Microsoft Store and reopen it.
2. Make sure Windows is fully updated:
   • Windows 11: Start > Settings > Windows Update > Check for updates
   • Windows 10: Start > Settings > Update & Security > Windows Update > Check for updates
3. Update Microsoft Store itself:
   • Windows 11: Microsoft Store > Library > Get updates
   • Windows 10: Microsoft Store > See more > Downloads and updates > Get updates
4. Clear the Microsoft Store cache:
   • Press Windows key + R
   • Type wsreset.exe
   • Select OK
   • Wait for the blank Command Prompt window to close and for Store to reopen automatically.
5. Run the Store troubleshooter:
   • Start > Settings > System > Troubleshoot > Other troubleshooters > Windows Store Apps > Run
6. Run the Windows Update troubleshooter:
   • Start > Settings > System > Troubleshoot > Other troubleshooters > Windows Update > Run
7. Restart the PC and try the update again.

If it is still stuck on reserving space, check free disk space in File Explorer > This PC. Low space can block Store app packages and updates. Freeing space can help.

If the issue started after cleanup and the Temp folder is filling with Store app files, Microsoft recommends this sequence:

• Reset Microsoft Store
• Clear the Store cache with wsreset.exe
• Run the Windows Update troubleshooter
• Restart the computer

If Store downloads remain stuck after that, the next supported step from the available guidance is to reinstall the Store app from Microsoft Store > Library > Install if the app appears there, or repair/reset the app from Windows app repair settings.

References:

• Fix problems with apps from Microsoft Store
• Free up drive space in Windows