>>7
That's one way, but a quicker method is to find the reset jumper. Check your manual, or look on the board's silkscreened labels for something like CMOS RST - it's usually a pair or trio of pins fairly near the battery or the BIOS chip. You have to unshort or short the pins, or swap the jumper onto a different pair, depending on the motherboard.
As for reflashing, you need to visit your motherboard's manufacturer's website and download the current BIOS for your model of board, along with the utility they supply for reflashing the BIOS. Make absolutely sure you get the right BIOS image for your make and model though! Reflashing is sometimes done without a downloaded utility, using a keypress during the power-on self test. Again, download/read the manual for your make and model of motherboard.