Vista time not updating
The CMOS battery sits on your computer’s motherboard and provides power to the Complementary Metal Oxide Semiconductor (CMOS) chip.
This chip stores information about the system configuration, including the date and time.
If you have never used the system registry before, ask someone who has.
The following is an excerpt from Change the Default Update Interval If your clock is constantly out of sync even though it says the sync was successful, the problem could be that your computer is losing time because of a system clock problem.
check that this issue isn't being caused by any Windows 7 desktop gadgets.
If you’re obsessed with seeing the exact atomic clock time on your computer no matter what, you may want to set up synchronization with a remote server.One of the things we take for granted is that clocks show the current time.