Installer stuck at 18% when upgrading from Windows 10 (10074 to 10122)

Are you trying to upgrade to Windows 10 preview build 10122 and the installation hangs at 18%? The following approach unblocked me, hopefully it works for you too – please let us know in the comments:

  • Download psexec.exe from sysinternals to e.g. c:\temp
  • Open an elevated command prompt
  • Execute psexec with the following parameters (try not to copy/paste):
    • C:\Temp\psexec.exe –s –i cmd.exe
  • A command prompt in the system context should launch:


Execute the following command:

  • rundll32.exe pnpclean.dll,RunDLL_PnpClean /DRIVERS /MAXCLEAN

Close the command prompt(s) and try upgrading again.
Consider leaving a reply if this worked!


Thanks to my friend Antonio Vasconcelos for troubleshooting this together.