A "CPU Fan Error" notice in the BIOS often means that the computer's BIOS or UEFI is not recognizing the CPU fan attached to the motherboard. This error is intended to protect the CPU from overheating due to a faulty fan. The following are some methods you may use to address and resolve this error: Examine the fan connection, Inspect the fan, and Replace it if it is damaged. Check the BIOS/UEFI fan speed settings, Reset the BIOS/UEFI settings, and avoid CPU overheating.