hi , I belive if the problem is not been resolved, I have a solution probaly worked for me in windows Xp home edition,may be vista do have these type of passward recovery.
try CLt + Alt +Del , the way we try to lock computer in network.
U might get a screen where u will be asked to enter the User name.
Put user as Administrator or Admin & leave passward as Blank.
Hope this work's for you.