MY DELL INSPIRON 8600 HAS BLACK SCREEN

Hello, MY NAME IS GILBERTO I HAVE A DELL INSPIRON 8600 I WAS DOING A SOFTWARE UPDATE AND ASK TO RESTART THE COMPUTER ONCE IT WAS DOWNLAOD I DID IT AND WHEN IT START BACK ON THE SCREEN WAS BLACK WITH A BLINKING DASH BAR ON LEFT UPPER CORNER OF THE SCREEN PLEASE HELP ME I TRY EVRYTHING THAS SUGESTED HERE NOTING HAS WORK SO FAR I APRECIATED.THANKS.