The CMOS (complementary metal-oxide-semiconductor) is a small chip on the motherboard that stores the BIOS settings, including the date and time. The CMOS battery is a coin cell battery that provides power to the CMOS chip when the computer is turned off, so that the BIOS settings are not lost. If the CMOS battery is discharged, the CMOS chip will lose its data, and the date and time will be reset to the default values. This will cause a message to display indicating that the date and time are incorrect when the computer is turned on. The other computers on the network do not display this message because they have functional CMOS batteries. The most likely cause of this issue is the CMOS battery is discharged, and it needs to be replaced with a new one12.