You probably had a password… If so your files are encrypted :( You did mistake installing 2nd and 3rd copy of windows, all you had to do is to take hard drive out and attach it to another PC and do check disk, it would fix your problem or just do repair install. If you can do it, try this: insert XP cd, on start up it will ask what you wanna do, press enter -> F8 -> then choose your first XP -> then choose repair. otherwise you will have to use password crackers to clear you password