Windows unable to upgrade due to USB install of OS

 Windows unable to upgrade due to USB install of OS Windows 8.1 / Windows 10

  • opening a cmd.exe as admin, run this command: reg add HKLM\SYSTEM\CurrentControlSet\Control /v PortableOperatingSystem /t REG_DWORD /d 0
  • Then reboot.

*Windows uses this PortableOperatingSystem key to detect if you use a regular or WindowsToGo version.