The main cause for a computer to lose time is a weak or dead CMOS battery on the motherboard. The purpose of the CMOS battery is to keep the BIOS settings such as time, date, and hard drive parameters alive when the computer is powered down. The battery is silver and about the size of a nickel in a holder on the motherboard. Most CMOS batteries in modern computers are model # CR2032 and are readily available at Radio Shack or your big chain drug stores and cost about $3.00 . Remember to unplug the power cord before replacing the battery. After installing the new battery you will have to go into the BIOS settings to reset the time and date. If you are not comfortable rummaging around inside your computer you should have a tech do it for you. It should cost about $15.00 or $20.00 dollars.

your clock is supposed to keep changing! tick, tock, tick, tock... time marches on. you'll get used to it.

Check your time zone setting and make sure it is set to the time zone you are in or it will automatically reset itself when you turn off your computer.

How and Where to begin when changing the CMOS battery: CMOS is an abbreviation for Complementary Metal Oxide Semiconductor. You may need to change your CMOS battery if your computer clock isn't accurate when you boot. However, if your pc loses time as the computer runs, that's another problem. It is important to get into the BIOS settings and write down any special settings. If you remove and replace the battery quick enough, you might not lose your settings, but it's best to write everything down. Remove the side panel so you have access to the motherboard. You should have the pc unplugged and be wearing an antistatic wrist strap to avoid damaging your boards. Jot down notes if you cannot access the battery directly and need to remove cables. Note the connection and orientation of each cable. Do not unplug anything from the board unless absolutely necessary. The battery is often only held in place by a couple of thin clamps that can be gently slid aside or raised enough to get the battery out. DO NOT BREAK THE CLAMPS. Once the replacement is in, replace any cables, close the case and boot the computer. Go back into the BIOS and restore any settings, if necessary.

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