Computer won’t power on after BIOS flash

I have an ASUS P2B-F mainboard. I am running Win2000 Prof. OS said that COM ports weren’t functioning properly so I flashed the Award BIOS to rev 113a. It loaded successfully. I rebooted, went into the BIOS and clicked on “Load BIOS Defaults” instead of “Load Setup Defaults”. I saved it and went into Windows with no problem. I shut down Windows about 2 hours later and turned the computer off. Later when I tried to start the computer I get a blip of power and the fan doesn’t come on. What can I do?