When computer starts shows screen with message CMOS settings wrong

1. When you get such errors, F2 should help you to load with previous settings, although the date and time might be wrong.
2. Try to change CMOS battery or see if it is loosely placed.
3. If the issue still persists, there is a Microsoft Community Forum, where you can post the error with the screen shot. Someone from the team can get in touch with you and help in getting the issue resolved.

Changing the CMOS battery will mostly solve the problem. If you know you can change the battery yourself. Otherwise you may contact your usual computer service technician and he can do that or diagnose any other problem. You may get the computer routine preventive serviced also during the visit.

CMOS is the small memory chip or part in the motherboard which stores BIOS setting including time and date.

Battery could be a reason and changing that might solve the problem. Many times the CMOS setting is disturbed and that can also give this message. In that case one has to go to CMOS setup screen and there will be a menu at the bottom of the page where function keys like F5, F6, F9, F11 or F12 will be mentioned along with their role and required option for CMOS setting is to be selected. Generally it is to be set to default setting or option to load fail-safe defaults. One has to use arrow keys to select the option function key and then enter. It will solve the problem.

Under such condition, Battery is the main culprit and the same is to be changed. Once you carry out this operation, function of your computer will be normal.
The other parameter to be looked into is BIOS system where the date and timing has to be adjusted. It is located at the right side of the screen.
You may take the help of a shop for the Battery - replacement and for the adjustment of BIOS.