I used to get these problems with my computer all the time. I don't know how to fix it without the formatting option. But in case you do recover it I found out a very solid preventitive measure so you never have to worry about these kind of issues again. It's actually relatively simple to tell you the truth. You can get this done at most computer shops too. I know you can at Future Shop. So say they are the store of your choice. First, go to Future shop. Then, buy a Mac.