Black Screen

Yesterday I suddenly got a black screen when I was browsing on my comp. I shut it off went to sleep and in the morning whenever I start up my computer it remains a black screen... The monitor button which shows the status is first orange, then green, then orange, then green and then it remains orange. Is this some kinda virus or something and if so how can I protect myself against it when I can't even open up anything. By the way I do hear the windows 'starting' sound. So can anyone help me out? Btw I'm on my moms laptop now.