if you have access to this machine, and can boot off the floppy, then there is a really easy solution

http://home.eunet.no/~pnordahl/ntpasswd/bootdisk.html

This disk goes in through linux, with NTFS read/write, and allows you to CHANGE the passwords of any local accounts. . .
it's basically the same thing as above, but it IS rather user-friendly, albeit a linux command line.