no boot, and you don't have the right to install apps..
as already suggested hardware way is the best.. another way is a web tool like:
http://lasecpc13.epfl.ch/ntcrack/ [Advanced Instant NT Password Cracker]
but unfortunatly the demo is not on-line anymore.. probably you can ask or search for similar projects
more info @
http://kennethhunt.com/archives/000640.html