You have two options:
1. Mechanically resetting by CMOS & jumpers:
Some, but not all, motherboard manufacturers provide a set of three jumpers on their motherboards.
*www.dewassoc.com/support/bios/images/piiisea_jump.jpg
The arrow to the left denotes the location of the "Clear CMOS" jumpers, while the red arrow to the right denotes the location of the CMOS battery.
A)Shut down your computer and disconnect the power plug.
B)Check the default pin settings & write them down somewhere.(Eg: a jumper across pin 1,2 can be default,etc.)
C)Place the jumper across pins #2 and #3, keep it for about 30 seconds and then reset the jumper upon the default location.
2. If no jumpers are present:
A) Shut down the computer and disconnect the power plug.
B) Remove the 1/2 inch circular battery from its slot, keep it for 40 seconds or so, then place it back to its slot & reboot.
This will reset your BIOS.
Even after this, the bios asks for a password, then it must be the default password.
Here's a list of default passwords:
AWARD Bios:
"Condo", "AWARD_SW", "J332", and "589589", "AWARD?SW", "lkwpeter", "aLLY", "j262", "j332". (without quotes)
Phoenix BIOSes
"phoenix"
Other BIOSes
"biostar", "biosstar", LKWPETER", "BIOSTAR", "j262", j256", "Syxx", "Wodj"
For a complete list of all default bios passwords, click here.