Undo Windows 7 File Ownership

JoelCT

Here is a real challenge for you. I have been building my own systems for many years, and know my way around all Windows Versions. This one has me stuck.

I get a new Hard Drive. I install Windows 7 on it. I then plug my old drive in, and discover the very cool way to change the ownership of all the "My Documents" folders and files on the old drive, which was running Windows XP. If you haven't tried it, it really works well. It allows Win7 to own all those old files so you don't have any trouble opening and changing them.

THEN, I find out that the legacy program that built some of those files just isn't going to work with Windows 7, for at least a few weeks. So, in order to get my work done, I unplug the new drive, plug in the old one, and boot up Windows XP. Guess what? Windows XP says I don't have permission to access those files any more. Even if I boot in Safe Mode as Administrator, I still can't even COPY them.

So, the question is, can anyone think of any ideas to "undo" the change of ownership that Windows 7 performed on my WinXP files? Thank you so much for your brainstorming ideas!