Cannot access user files after MB loss

I have a winner for you all, hope you can help. My surge protector was blown as was my mother board. I was running WinXP. I set my drive up as a slave on another machine running XP and can see all the files except my user files that are protected bywin xp logon password. I need some of these files. I know, should have backed up, but didn’t. I am denied access no matter how I try to circumvent the problem. I can share / access the drive fine just not MY files. Any help would be greatly appreciated.