BIOS are motherboard firmware that starts all hardware parts. BIOS permit to adjust different system and hardware settings. Default factory BIOS settings assurance that system will be steady and bootable. Improper or severe changes of BIOS parameters to get, for example hardware overclocking, may weaken PC or avoid system from booting up. CMOS is an included motherboard chip that stores existing BIOS settings and is powered from battery. If PC will not boot up because of previous changes in BIOS settings, CMOS is to be reset to restore default parameters. CMOS clearing is performed on hardware level and thus is OS independent.

Instructions

Remove CMOS Battery

1. Step 1

Turn off PC. Open PC case by removing side panel. Then put PC aside.

2. Step 2

Find CMOS battery that is placed in socket about in center of motherboard. CMOS battery is round, plane and half inch in diameter.

3. Step 3

Raise the CMOS battery out of its socket and set it aside on a part of paper. Wait five to 20 minutes. Put in CMOS battery back to its socket.

4. Step 4

Close side panel and push "Power" button to switch on PC.

Use a CMOS Jumper

5. Step 1

Turn off PC. Open PC case by taking out side panel. Then place PC aside.

6. Step 2

Locate "CMOS Clear" jumper on motherboard. This is generally placed near CMOS battery socket that us about in center of motherboard. This jumper is a tiny two-pin shunt installed on over three-pin connector. In default position, jumper is generally placed over first and second pins of connector. Take out jumper from 3-pin connectors using fingers or a small forceps.

7. Step 3

Put jumper over second and third pins of connector that is CMOS clearing place. Wait 10 to 20 seconds. Take out jumper from 3-pin connectors once more and install it in default position over first and second pins of connector.

8. Step 4

Shut side panel of case and push "Power" button to switch on PC.