Hey, and welcome to the forums! From what I understand, you're going to open up files, from a Windows XP PC to a Windows 7 PC? Well, that shouldn't be a problem, and it should work, as long as nothing is manually deleted. Am I correct, thats what you and your dad are trying to do?
Edit: @whs, I just figured he would have used a 3rd party program to update auto, but that makes sense. +1