HELP! Okay, I have no idea what happened. I didn't do anything in my daul boot process and already my drives are screwing up! For some reason I cannot access my 100GB drive (drive D:). The first time I tried to enter it, it said something like "D:\ is not accessible The parammeter is incorrect"

Then I noticed that somehow, I have a new drive on my system called H:, and when I tried to open that drive I got the same error. Then when I tried D: again, I was told that the drive wasn't formatted, and it asked me if I wanted to format it! What's going on!? This drive has all of my important files on it. I have to access it!