Boot Problems

I have a computer that I built about 2 years ago. It has been working great. Asus PC8000 E board with 512 ram and 200 gig hard drive and ATI Radeon 7500 All In Wonder Card. Again it has been working great but a few weeks ago our power went off. When it came back and I rebooted it would not boot. It would go to the F5 screen and it would let me boot into safe mode. When in safe mode I would reboot and it would boot up again the right way. Yesterday I had to reboot it and now it will only boot into safe mode. Today I booted into safe mode and uninstalled the video card and then it did boot up fine. I then found new video drivers and to test it I rebooted again. Now it will not boot up again except for safe mode. Ive tried unplugging all the devices and then booting up that that did not work. Nothing I do will let it boot normal, just into safe mode. When it did boot up, it worked fine with no problems. Could this be a hardware problem or a driver problem? The last thing I installed was Norton System Works. I don't really think that is the problem but who knows. Any help is appreciated. Thanks.

Tom