lately,I have to reset the date time on my computer,also when I first
start it up,it tells me to press F1 for setup..

Your CMOS battery on your Motherboard has failed. You need to change it
soon. If you turn the computer off for too long a time, it may
completely scramble CMOS RAM, stopping the computer from booting. No
big deal if that happens, since it's easy to get into the BIOS setting
and reset to defaults, but it can be disconcerting when all of a sudden
the computer just won't boot at all.

HTH

Twayne