You know... I just remembered something quite funny: One of my first rookie mistakes was getting myself locked out of the administrative account.
Anyhow, there's a solution: What you need to do is to download a software called "Offline NT Password & Registry editor" and burn it onto a blank, bootable disc. Once burned, insert the disc and restart your computer (make sure BIOS settings are configured to boot up from CD-ROM first).
The interface itself is quite user-friendly and all you need to do is follow the instructions. After a few quick steps your password should be removed. Visit This site for more information about the software. As with any, do use with caution.
"I'm tired. But then again I'm so hungry I can't sleep. But what's the point of eating if your sleepy?" - Sniff, The Moomins.