Is not turn on

Hello, my laptop is lenovo G510. I was working in
my laptop it asked for windows to update n restart
computer.i choosed one hour later option.after one hour
the laptop is gone to automatic restart.during restarting
laptop is automatically setting something.n it was showing 1%
,2%....100%.n i guess it was not a windows update setting.after that it ask me
express or customize setting?i choosed express n then
laptop is trying to open its windows,mouse is working
sometime.screen is black with some light from inside(on the way of opening with
black n white screen),fan is working inside.l tried to turn
off it,remove battary n replaced again but didn'work.my
laptop is still trying to open n i only see the mouse pointer
in black screen.i hope u understand my problem
i will be happy to get the solution.