Go to the BIOS and load the default settings. You need to hit F2 (or one of the F keys) to go to BIOS.
Do you mean enter the BIOS screens ? -- usually press Del or F2 key at boot up.
Do you mean reset the BIOS as per on a desktop computer where there's usually a jumper to do that ? Not so easy with a laptop -- best bet is to try to get into the BIOS screens and reset to defaults or a "safe" setting.
If the thing just won't start, disconnect the power cube and take the battery out. Then press the power button and then resinsert the battery and try to start it.