every time when i switch on the computer shows error and the clock shows time 1/1/99 that i have to correct?

Question

then only i am able to load the computer fully every time at start it is happening what is the proble please advise me my battery is new

Answer 1

you need a new battery on the motherboard.
it is usually a cell/watch type battery.
generally they start to go bad after 5-7 years.
depending mostly on how much time your computer spends off.
the battery maintains settings like time/date/etc

Answer 2

if you have a new motherboard battery it sounds like a bad connection with it, check the connections and try it again, or the battery could be faulty

Answer 3

change your cmos battery on the motherboard

Answer 4

y2K bug