cmos checksum error
Easy Fix
Microsoft · Windows
The BIOS settings stored in CMOS memory are corrupted or lost — the checksum verification of stored BIOS settings does not match, usually because the CMOS battery has died
Quick Answer
Error code CMOS Checksum Error on your Microsoft Windows means: The BIOS settings stored in CMOS memory are corrupted or lost — the checksum verification of stored BIOS settings does not match, usually because the CMOS battery has died. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
The most common fix is replacing the CMOS battery. Power off the PC, unplug it, and open the case
2
Locate the CR2032 coin cell battery on the motherboard — it is a silver, round, flat battery usually near the bottom of the board
3
Note the battery orientation (+ side usually faces up), release the retention clip, and remove the old battery
4
Insert a new CR2032 battery in the same orientation. These are available at any electronics or convenience store
5
Power on the system. You will need to re-enter BIOS (DEL/F2) and reconfigure your settings (boot order, date/time, XMP profile, etc.)
6
If the error persists with a new battery, try clearing CMOS using the motherboard's CMOS clear jumper or button, then reboot
Pro Tip
This is a common issue that most users can resolve without specialized tools. Try the first step before moving on to more complex solutions.
Parts You May Need
CR2032 coin cell battery
Related Error Codes