i have hp elitebook 6930p but i cant use it i dont know administrator password how can i reset i taken of cmos battery between 5min-2 days ssytem recovery has occured error 500 again bios administrator if i push F1 or F2 or F9 F10 if i dont push any bouton ntrl missing dvd room and usb locked after 3 times wrong password system locked how can result this problem