How can I get my files from the external hard drive?

I took the hard drive from my old computer (it used XP) and hooked it up to my new computer (it uses Vista). I can get to the music and stuff from my husbands profile on the XP hard drive, but all my stuff won't open. I put a pword on all my stuff (we had nosey houseguests from time to time). He didn't. Is there anything I can do to get into my files? I want to format the XP hard drive, too. Will I lose everything if I do that?