I think there is a way to gain admin acces with ntfsdos pro and chtdisk, and then use pwdump2 and L0pht.

But ntfsdos isnt working on my comp so cant help you a lot

If you want exact detail:

1. Boot with an Ms-Dos boot disk, run ntfsdos pro and mount partition
2. Copy SAM on disk(for back up)
3. Use Nt password recovery tool to reset password
4. Extract password with pwdump2 and save output on disk
5. replace new SAM with old backup SAM
6. Wait on your super computer to crack the pw file with L0pht

And you have admin password!