My win xp system keeps changing date back to 2002

Recently, i noticed my system has been changing its date back to 2002 as soon as I put it on. This happens when a dialog box for Sounds and Audio Devices Properties pops up. Even after resetting, it will cahnge back to 2002. Could this be a virus problem or a CMOS Battery problem? I have changed the CMOS but the problem is persisting. On the Run box, when I type regedit, it also pops up the Sounds and Audio Devices Properties dialog box instead of the regedit box. Any one has ideas? Pls help urgently.