I've tried to go back to a restore point when that problem occurs without any luck. When I go to put in the repair disk so that I can load the system image, it wants to repair my boot settings but even that doesn't help either. I'm hoping that changing the default OS might help.

Yes a backup image is a must if you do any experimenting on your pc. I've restored my pc from a backup image SEVERAL times with 100% success. Windows 7 has a great backup program. I make an image twice a week.