Problem with Invalid System Time

[jasonlimvm]

Hello,
I own a compaq nx7000 laptop with windows XP. I have recently encountered an "Invalid System Time" alert pop-up message box appears everytime I login.
The message is as follow:
"The time or date on your system is invalid. Please use the date/time applet in the Control Panel to properly set your system time and date."

After changing the time system, I did a virus scan but found nothing. Now, whenever I log into the Windows, the system time keeps on changing back to "January 1980 12:00AM" and the above mentioned message box keeps appearing.
What should I do to resolve this problem?
Please help.

Thank you.

[stober]

check all batteries -- one or more may be low which will cause it to lose the clock time

[PeejAvery]

There is only one battery that controls the time and date. The BIOS battery. If the computer is new, this SHOULDN'T but could be the problem. Instead of opening up a laptop which can be a hassle, plug the laptop in and restart it. With power to the motherboard the clock should not reset. Then restart it without being plugged in.