I have finally found a solution, you have to enter the following in a DOS box. Winnt32.exe /encrypt:"XXXXX-XXXXX-XXXXX-XXXXX-XXXXX:5" /unattend:winnt.sif First in cmd you have to go to the location where the winnt.sif file is located, en then enter the above command. '5' are the days that the key is usable, after the 5 days you have to enter a key again. You can ofcourse enter 999 days, for example, so it will be usable for a long time.