Bios virus

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BIOS viruses are extremely r-a-r-e and more than likely it's a corrupted CMOS, bad CMOS battery, bad PSU or failed MOBO - and in that order.

I would first try to use the 'Clear CMOS' jumper method per your manual. Unless your system is stable in the BIOS then don't attempt a BIOS flash.

D945GCNL http://www.intel.com/p/en_US/support/highlights/dsktpbo...
BIOS How to -> http://www.intel.com/support/motherboards/desktop/sb/CS...
IMO use the F7 method -> http://www.youtube.com/watch?v=Q8r2cfcNIeE

BIOS Update [NL94510J.86A] -> http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&...

{Source} http://downloadcenter.intel.com/Product_Filter.aspx?Pro... Select OS then Select BIOS and look below