Help with Win XP SP3 ……………?

Anytime i begin my desktop it shows a meaning “CMOS checksum problem.Defaults full.” Click F1 to continue.When i do a similar it boot styles normally with virtually no further problems but the time plus date tend to be set to the date involving manufacture of the system.
I’ve tried a number of virus inspections, cleanups, defrags for example but next to nothing seems to work.Is formatting the only way out and about I make use of a Windows EXPERIENCE SP3 as well as i don’t desire to format this system as of this moment.
Any help are going to be greatly loved.(Please allow it to be easy when I’m not necessarily computer informed.)

Your CMOS battery power is dead/dying.You have got to replace the idea (it’s a smallish coin molded battery about the motherboard.You will get a brand-new one with Walgreens or something).