cdanteek- Your last post states that once the computer is booted up in XP, the bios must be changed or else the computer will be booted back into XP. That's not so. The Bios is set that when booting up the computer, and without doing anything else, the computer boots up into Win7. If when in Win7 it is decidedto now boot up into XP, then the computer is restarted and F10 held down. Now when in XP a decision is made to boot back up into Win7, all that's done is to go to restart and the computer now boots up into Win7. Again, without pressing F10 or anything else. Having explained this, it's based on my understanding of what you described. Pardon me if I misinterpreted what you describe.
By the way, after a third attempt at modifying the registry according to directions provided in the Windows Seven Forum of a workaround to prevent XP from deleting restore points in Win7, the workaround is a success. I can't explain why it required three attempts, but it did in my case. Even though restore points are no longer deleted in Win7, my plans are to use backup to create disk images.