Dell Latitude D600 Administrator Password

I am currently trying to log on to a Dell Latitude D600 running window 2000 professional, I have the administrator password and can change all the set up stuff that I need (HDD password, config password etc.) but when I boot up and the user sign on dialog box appears I can not sign in .. I even tried to go through safe mode ..I tried using admininistrator as the user name and also tried leaving it blank ..I guess what I am asking is if there is some special trick or way to sign on with the admin password in windows 2000> THANK YOU MUCH FOR ANY HELP