I am working on an old HP pavilion a300y PC. The problem is with the Bios & time. There is no CMos battery in these models & so if I update the time & date in the bios, it'll be ok till I power of the PC. That is unplugging it from a power source. Then it reverts back to the original factory setting. How can I overcome this when there is no Cmos battery to retain same ??

