No lights

Hello,
my screen display lights stopped working after what appeared to be a worm attack. im runnin a dell inspirion 1501. at the time i was runnin with vista ultimate, but now im stuck with basic( what it came with). iv lost all personal files but thats ok. i jus want the damn lights back cause who the hell uses a flashlight in middle day while outside thats what i have to do to see the screen. help pls.