Hey ... Did you by chance use this legit OEM xp pro version license keys on a different computer prior to this computer ? OEM is branded on the computer it gets used on ( one computer only ), What I would try now is either a repair install of a fresh clean install , Repair will keep all your data intact , a clean is a fresh new start , If after all that and you still have this problem ? Then go back to the place where you got it from and get some answers
Have a view at this webite below
http://www.informationweek.com/LP/sh...1&query Text=
HIH