why my PC's date and time is always wrong?

i have windows xp. i always correct date and time but when next time i switch on the pc, date and time are again wrong. please help me. 10 pts.

bluesceenofdeath2012-03-12T08:17:33Z

Favorite Answer

Need to replace CMOS battery, it's a CR2032 and you can find one at most store (drug store, walmart, Kroger) for under $5. Go here to see how to replace http://www.computerhope.com/issues/ch000239.htm

Lesus2012-03-12T14:55:35Z

The CMOS battery needs to be replaced, or the time zone is set wrong. Or if it's an old PC, you may need to update it for the new daylight saving time rules that changed in 2007.