If all you are trying to do is access the computer that you don’t have a password for, there are a few things you can do.

Pull the hard drive, place it as a secondary in another computer. Delete the SAM and SAM._ files. Put it back in the first computer. NT (or 2k) will recreate the SAM with a blank password for the admin account. (you will loose all the other accounts to).

or:
Get a full version of NTFSdos and boot from a floppy, delete the same files, same result.

If it is as you say your computer, cracking the SAM should not be needed.

Hope this helps.