What is CMOS-CHECKSUM-ERROR?
CMOS-CHECKSUM-ERROR is a medium-severity hardware BIOS/UEFI problem. BIOS detected invalid data in CMOS. Settings have been lost. It sometimes comes down to power failure. Work through the steps below in order.
Common Causes
- Low CMOS battery
- Reset BIOS
- Power failure
Step-by-Step Fix Guide
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1
Replace the CR2032 battery
Replace the CR2032 battery tends to be the quickest win here, addressing the most typical cause of CMOS-CHECKSUM-ERROR.
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2
Reset date/time
Not every case resolves on the first try; the steps that follow cover rarer bios instability situations.
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3
Save the BIOS settings
This step, "Save the BIOS settings", specifically rules out reset BIOS.
Commands & Diagnostics
No specific commands required for this error. Follow the step-by-step guide above.
Frequently Asked Questions
Low CMOS battery accounts for the majority of CMOS-CHECKSUM-ERROR reports; reset BIOS and power failure come up less often but are documented.
The fastest fix is "Replace the CR2032 battery". Only move on to the later steps if CMOS-CHECKSUM-ERROR keeps coming back.
CMOS-CHECKSUM-ERROR is a medium-severity issue. It can affect system stability, but the fix steps above typically resolve it without lasting damage.
In most cases, yes — the guide above resolves CMOS-CHECKSUM-ERROR without a clean install. Treat a reinstall as the last resort, not the first move.
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