Hello,
We're gonna try something but you have to follow directions carefully or you could risk ruining your installation of Windows.
EDIT:
As suggested by
Rabmac you should backup your registry prior to following these steps. I have provided a guide to doing this below. This will allow you to recover should you accidentally change the wrong value or delete a key or any other potential mistake.
■ Download the ERUNT zipped file here: http://www.bleepingcomputer.com/download/erunt/dl/97/
■ Extract the files to your Desktop and launch "ERUNT.EXE"
■ Check both System registry and Current user registry, choose a location you will remember for your back up and click OK
END EDIT...