CMOS checksum error is a conflict between the CMOS (Complementary Metal Oxide Semiconductor) and the BIOS (Basic Input Output System) when booting the computer. This occurs when the computer cannot read startup information or the data does not match.
There are many potential causes of CMOS checksum errors, but almost all of them result in the CMOS information being corrupted in some way.
Before the operating system boots up, the computer's motherboard handles many lower-level tasks, preparing system components to run and ultimately handing off these tasks to the operating system. The software on the motherboard is called BIOS. In addition to booting the computer, the BIOS contains various hardware settings such as speed, voltage, system time, and boot priority. BIOS settings are not saved on the hard drive. They are on a chip called CMOS.
These events are written to CMOS whenever you change BIOS settings, start the computer, or shut down the computer. It tracks data to make sure everything is running properly the next time you start your computer. When the rest of the computer is shut down, the CMOS remains on because it is independently powered by the watch battery. When the computer starts, it reads the last state it was in from the CMOS. Usually, it reads the information and recovers on its own without any problem. CMOS checksum errors occur when the computer cannot read this information.
One of the most common causes of checksum errors is also the easiest to fix. The battery powering the CMOS is a watch battery and it can become drained. When the battery dies, the CMOS can no longer store information.
Power surges and sudden power outages are other causes. If a computer doesn't have a chance to write information to CMOS before a sudden power loss, it has a hard time continuing where it left off. Power surges can also cause damage or damage to hardware.
The final cause is less common, but it can happen. If the BIOS is damaged or corrupted, it will cause a BIOS and CMOS mismatch. It is uncommon for a virus to infect and corrupt the BIOS, but it can happen. However, a more common scenario is that the BIOS update fails or the operating system updates something that causes it to become out of sync with the BIOS.
While it's not always possible to fix CMOS checksum errors, especially if the hardware is damaged, the fix is usually simple. Perform the following steps in order to resolve the error.
Restart the computer. A graceful restart will usually create a new checksum and eliminate the error. Errors that persist after a normal restart require more work.
Download and flash BIOS updates. Download the update from the motherboard manufacturer's website. Many motherboards can download updates from the BIOS when plugged into the network using an Ethernet cable.
Reset BIOS. Some motherboards have a switch on the motherboard or on the back of the computer that resets the BIOS settings. If there is no such switch, remove the CMOS battery from the system for a minute or two. A loss of power causes everything in CMOS to reset.
Replace the CMOS battery. If the cause is a dead battery, you just need to replace it with a new one. The CMOS battery is located on the computer motherboard. On a desktop, it's easily accessible and simply held in place with a metal clip. On a laptop, you need to open the machine to see the motherboard, which is probably best left to the professionals.
Please consult a technician or computer repair expert. If all the above methods fail, the problem may be caused by damaged hardware. Before buying a new motherboard or recycling a machine, have it checked by a professional to make sure it's safe.
A checksum is an algorithm used in many programs to confirm the integrity of a file. This is often used in downloaded programs to confirm that the file has not been tampered with or corrupted.
Try using WinZip to repair the file. To do this, right-click on the file and select Extract File . Next, go to "Other" and place a check mark next to "Keep corrupted files" and then select the extraction location and select "OK" .
