It depends, first, did you open an e-mail that said 'Hallmark Card' or something? If so, your computer has a virus. This virus burns your Hard disk C and you can't open it again until you get an anti-virus thingey. When it's all installed, shut your computer down for 24 hours to let it all soak in, if you turn it on too early, you will have to do it all again and your C disk won't open until it soaks in. You may even have to let it rest more than 24 hours if you have an old computer or a laptop. If you follow these directions, you can open your Hard Disk C again, if not, try a different anti-virus thing and repeat the process. I heard about this on the news, but don't know what a Hard Disk C is. Will you tell me?