How can I fix system time error?

Please clarify your question.

Often system time erros occur when the motherboatd backup battery (keeps the cmos memory intact when the system is off) starts to go bad. Normally the power of the machine when it was on would recharge the battery but they do not last forever. On newer machines the batteries can be found on the motherboard and they're a little larger than a nickel. Mine are CR2032 3 volt. Power off the system from the wall for 30 seconds or so before going inside, and try not to mess with anything else but the battery (most have a small pressure point along the side that holds the battery down and that's a good spot to get it out with a small jewlers screwdriver or similar and put it back in by hand angled down to that point first so it doesn't block insertion. Once a new batery in in you should enter setup or the bios and set system defaults or optimized defaults if your brave. That setting is typically in the last row where you also save and exit.

I tried to change a new cmos battery.. then I go to system set up . I tried to change the system time, and its done, but after a few seconds.. the time back on its default time..

Its abnormally unadjusted!

My system time isn't updated! I try to adjusted it, but an error occurs " you do not have the privileged level to change the system time. " I changed already a the old cmos battery to new.. but it's the same error come up! The only chance is is to disable the depreeze so that I can set up the time and date in my comp. plzz.. show me what are the steps in disabling and enabling a depreeze..

OK, try going into control panel and then "Date and Time" and see what Time Zone your set for. It's always nice to have an extra battery on hand,but if the old one was OK I think I would put it back and save the new one later.