Ebuka, seems to be a pretty common error. "If your notebook's BIOS becomes corrupted, such as from a failed BIOS upgrade or damage from a virus, then the computer fails to boot into an operating system. The computer may display the error BIOS APPLICATION ERROR 501 or simply stop at a black screen or beep. You cannot enter the BIOS Setup Utility or System Recovery screens, nor will the computer start from external storage devices." Check this [http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&lc=en&dlc=en&docname=c02693833|HP site] for a resolution. Hope this helps, good luck.