Ok, so I Have win XP on a partition. I want to rename a file, that way instead of opening logon.src it would open cmd (that way I can have access to the command line prompt) because my friend forgot his password and I want to reset it.

If I do that, is there a chance of damaging files or something worse to my Windows XP?

I am using Knoppix Live CD 3.x. How do I access my windows partition files when booting with the live cd?