My computer clock was doing fine while the computer was on, but losing hours every time I turned it off.

So, I replaced the CMOS battery (standard, CR2032).

Now the clock is slow even when the computer is turned on! This is irregular. In ONE session, it got slower and slower, to the point that it was hardly changing at all. I have no idea what the problem is, so I'm trying the Windows forum.

I have Windows XP, HP Pavilion, Zone Alarm and Threatfire security.

Any suggestions?From what I can guess, it looks like your bios clock is dying (or perhaps dead already). You could try turning on "time SYNCHRONIZATION" in Windows to compensate, however I don't know of any other solutions other than REPLACING the motherboard, or getting a new computer.I would try a new battery...some of them have been sitting on the shelf for awhile depending on where you got it.Thanks to you both, but, interestingly, the problem seems to have gone away on its own. My clock is now, again, keeping good time while the computer is turned off and has gone back to working normally while it is turned on.

I don't think I have a bad bios or motherboard -- remember, the problem started with the clock failing only while the computer was turned *off*. To me that says "battery" rather clearly.

I suspect that while the battery was dying or being replaced, some system function or timed activity (update, virus check....WHATEVER) got out of synch with the given time. It had to get past all the bad times and reset the time to a correct one for the system to "catch up". Just a guess, but makes sense. At one point Zone Alarm insisted on doing a complete check for updates, even THOUGH it had just done so. It was confused by the time changes.

Does that make sense to you?