My wifes PC which I built about 2-1/2 yrs ago won't keep time. I have the latest Bios & I've changed the battery out 2 different times thinking that maybe the new battery was bad. She will set the time & it might run ok for 2-3 days & then when she turns it on it will give her the error to hit F1 for setup or F2 for defaults. It a ASUS P5B with an Intel dual core chip (can't remember which one right now). Any ideas? is the RTC chip bad.