Most people never set a BIOS password. there is no need to.
Follow these steps:
1. Turn off the Computer
2. Unplug the power cord and if it is a laptop remove the battery.
3. Open up the computer case and remove the CR-2032 Button battery mounted on the Mother Board. Leave it out for at least 30 Minutes. This will reset the BIOS to Default values with no password.
4. Re-insert the Battery and start up the PC.