The standard CMOS configuration screen includes settings for items such as
Date
Time
Floppy disk drive types for drives A: (first floppy disk drive) and B: (second floppy disk drive)
Hard drives connected to the IDE interface
firmware chip
By entering the CMOS setup you are able to change the boot sequence of your computer, enable or disable RAID, and change power-on settings. The CMOS setup also allows you to view and change floppy, hard drive, and optical drive settings, as well as change a number of other hardware configuration options.
Cmos ram.
F2
Most computers have a keystroke (usually esc, del, or F12) that will interrupt the boot sequence when you start your computer. In the past, this would be when the white text flies across the screen displaying memory available, hard disk sizes, etc. This will get you into the BIOS for "cmos setup". CMOS is a type of memory that does not lose its data on power loss. In earlier computers, this is where the boot up configuration was stored; hence the phrase, "setup cmos"
date time change and window starting problem
Josh Rogers page 12 section 4-5
To access the CMOS setup on an HP ProBook 4520s, restart the laptop and press the "Esc" key repeatedly as it boots up. When the Startup Menu appears, press "F10" to enter the BIOS setup. From there, you can navigate through the CMOS settings using the arrow keys. Be cautious when making changes, as this affects system configuration.
No, not all systems use the same method to enter CMOS setup. Some systems allow access to CMOS setup by pressing DEL during start up and others by pressing F2.
CMOS Setup
Most likely the small battery inside the case that powers CMOS RAM needs replacing.
yes it is stored in CMOS