Plz Help me

PLEASE HELP ME SOLVE A UNIQUE PROBLEM
I have a serious problem with my hp pavilion zv5000. a few weeks ago i set it on standby mode while it was downloading some stuff by utorrent and i went to sleep.that night there was a thunder strom and very massive lightining.in the morning when i saw my laptop it was off.when i turned it on ,it started normally,after using a few minutes, i came to know that it is muted when i increased its volume from the volume icon it automatically became muted.not only this when i opened any window or page ,it was automatically closed if it was maximaized.another problem which occured was mouse pointer became hanged, inspite of moving finger on the trackpad it did not move, but the pointer automatically moved to start menu open several programs from there.this problem is persistant till now.i have installed several antiviruses but no one detected any virus.i formated the whole hard drive but i can`t get rid of this problem..........
PLEASE HELP ME OUT..........