hi you need to replace the cmos battery.
turn it off. then flip it over unscrew the memory cover just above the main battery you willsee a little pill shaped silver "watch" battry gently prise it out and replace with anew one. possibly the shop will do this for you if you buy it from a friendly computor shop.
just done this on a 380 that I found dumped...and it lives again!
if you dont it will eventually not boot at all.
but you can download amanual for free at the lenovo? site that will explain it better
sg88
April 2008