The link to reset the password requires that you've previously created a password reset disk, which will let you into the following procedure, according to the MS site:

What to do if you forget your Windows password

If you've forgotten your Windows password and you're on a domain, you should contact your system administrator to reset your password. If you're not on a domain, you can reset your password by using a password reset disk or by using an administrator account.

If you forget the administrator password and don't have a password reset disk or another administrator account, you won't be able to reset the password. If there are no other user accounts on the computer, you won't be able to log on to Windows and will need to re-install Windows.

I haven't followed this through, but it sounds like a re-install of Windows is what Uncle DaveO will need to do.