Change the CMOS Battery

The first signs that your battery is failing is that your clock began to run slow & you will notice that your computer keeps forgetting the date & time or your computer is having an issue finding & accessing positive peripherals or your PC refuse to boot, displaying a "CMOS Checksum Errors" or "System Configuration Lost message". When you experince those signs it's time to change your CMOS battery.

Before you jump on replacing your CMOS batter, safety rules first. The inside of a computer is a bad place filled with electricity & sharp edges. Make positive that your computer is unplugged from it's power source. Even be cautious on the inside of your computer,  most computer cases are unfinished metal & has sharp edges.

Here are the following tools you need to change your CMOS battery :

1. a X-point screwdriver

2. an anti-static strap(optional but recommended)

3. a new battery (seems logical)

 Then, this is the steps :

• First, When you remove the elderly battery from the motherboard, the information that's stored in the CMOS will be lost, so you ought to write down the BIOS settings.
• Unplug all the cables from the back of the computer, in the event you are not familiar about the ports at the back of your computer you ought to make a note  on where they came from so you can basically put them back when your done.
• Move the computer somewhere where you can work on it with ease.
• Remove the cover by locating the screws around the outer edge  at the back of your computer. Some computer cases only need you to remove four screws on side then a panel can be removed allowing you access to the computers insides, others you must remove 6 screws & remove the whole case by sliding it to the rear & lifting it off.
• Now make positive that you read & understand the safety instructions about static. Dangers of a Static Electricity
• Look inside & will see a round silver thing that's a size of bottle cap. Carefully lift the retaining clip & slide the battery out.
• Back to your computer insert the new battery by lifting the clip & sliding the battery in.
• Reinstall your case & plug all the cables back (you did keep in mind to label them didn't you)
• Power on your computer & check the bios, In the event you look carefully you will notice a line that says something like press del for setup or some other key (F2 or ESC or tab) this will take you to god's house (the BIOS) where you can make lots of changes to the way your machine works.
• You will now be introduced with a blue screen with lots of options on it, The they would like is load optimised/default settings.
• Exit & save your BIOS setting, your computer should now reboot.