Help with the system checksum CMOS

[salt and pepper]

Hello,
I took my laptop in for repairs because the date and time, system checksum cmos bad -defaults configs used kept coming up i am not computer savvy and do know how to change date and time but i dont know how to change defaults configs without messing up laptop can use computer after setting date and time but every time i shut down have to reset time and date is there someone who can tell me how to use configs on laptop using all the f1, f2, etc #s

 

[WR2]

Hello salt and pepper;

When the date/time can't stay upated correctly and the BIOS forgets custom configs it's likely your onboard CMOS battery needs replacing.
What kind of repair took place when you took the laptop in for repair?

Is there any reason you don't want to name the make and model of your laptop?

 

[salt and pepper]

Thank you for all the answers to my question
1. im not sure if my CMOS battery needs to be replaced ,all the work that was done was OS Win ReInstalled-Windows Setup Updated i already had Windows just wanted system checksum CMOS fixed guess that didnt happen also my laptop was a gift and its a IBM ThinkPad with the little red dot in the middle of keyboad to move the curser. I like it its 121/2 in. in width just the right size for what i need to check my emails, play pogo game, look up things on the internet if there is something more i can do myself sure wont turn down any help Thank You Again