grrr compaq nc6320 is TOO secure!!

OK,,, I am cheap and really can’t afford to go to a big computer store and buy a brand new PC or Laptop. So I resort to Pawn shops and classifieds for things that I want that are out of my price range. (I live in Vegas…nice things in Pawn Shops) Anyways…. I purchased a Compaq nc6320 and I can’t get in it at all…..It boots, but then there is a security screen and the windows xp pro logon. So…I put a new(used)hard drive in hoping to reinstall XP pro and be rid of the logins and so on. But here is the clincher….the Compaq says there is no hard drive. Mmmmm…. Its in there…I put it in there….help….I hate to have to trash this…Im too poor…LOL