sysprep cannot run on a computer that has been upgraded from a previous version

Error: "sysprep cannot run on a computer that has been upgraded from a previous version"

For what ever reason like me you need to sysprep a Windows 7 computer or even a 2008 Server that you upgraded from a previous version of Windows\Server but receive the error above.

FIX:

Delete the following Reg Key hklm\system\setup\upgrade