The exact error message would be very helpful.
It sounds like a surge may have damaged something, or at the very least screwed up your BIOS. I'd remove the RAM, disconnect everything from the motherboard, and leave only the CPU, one stick of RAM, and the video card installed, then boot into BIOS and restore defaults, reboot, then configure your BIOS the way you want it. It would also be a good idea to test your RAM and your hard drive. Once you post the exact message it may be easier to pinpoint the problem.