How do i clear the cmos on my asus p5nsli

Do you have your manual? Open it to page 1-9. See motherboard layout on page 1-9.
The bios /cmos jumper is to the left of the front panel pins, lower right hand corner.
The MB bios jumper is marked, CLRTC. It’s just above the chassis pins.
Clear cmos page 1-25. It’s pretty tight down there. Tweezers work well.

Cheers!
Mike

support.asus

just to clarify, to clear your BIOS, there should be a 3 pin set on your board usually located some where just below your RAM. On the board will be printed something like "CLR" or "CLEAR" move the pin connector, with the power off, from its current position to the middle pin and the open pin. Wait about 15 to 20 seconds and move the connector back to the original position. You have just reset your bios to factory defaults.

Dear,
You can select set default option. This will make your BIOS to factory defaults. Or if you need to upgrade your BIOS to new version You will get it here Downlaod->others> http://usa.asus.com/Product.aspx?P_ID=JCYhbJmty7zBzLL2&content=specifications