To get access with a Knoppix Live CD go to the "Knoppix" submenu, open the root shell, type "passwd", enter a password, verify it, and you can Login as root and do your file access and copying. I just used Knoppix to rescue a totally DOA Win Xp machine and a dead 98SE machine. There is a good Knoppix howto at http://www.shockfamily.ne/cedric/knoppix/
it gives more details on how to access dead machines. It kind of leans towards MS but you can get the idea. Good Luck, it worked great for me.