We recently got a computer that has Windows XP Professional installed on it. The only account on the startup page is "Administrator" and it has a password - we don't know the password and the person we got the computer from doesn't know the password.

Is there a way to reset or change the admin password? I found a possible way to do it but it requires using the "Guest" account; there isn't even a "Guest" account listed so I have no idea how to get past the startup page at this point.

Really the only way round this is a reinstall of the OS.
You'll need either the restore disc for this machine model or a Win Xp install CD.

hehehe... before trying CurlyBen's suggestion, have you tried asking for the password from where you get the computer?

hehehe... before trying CurlyBen's suggestion, have you tried asking for the password from where you get the computer?

Psst
we don't know the password and the person we got the computer from doesn't know the password. Hence my suggestion ;)