MSI P45 Diamond Series Manual page 29

M S-7516 M ainboard
Clear CMOS Button
There is a CMOS RAM on board that has a power supply from external battery to
keep the system configuration data. With the CMOS RAM, the system can automati-
cally boot OS every time it is turned on. If you want to clear the system configuration,
use the button to clear data. Press the button to clear the data.
Important
Make sure that you power off the system before clearing CMOS data.
2-14