I've had the same problem with my DVD-Rom-drive once, which had disappeared as well and then a week later my D: drive was gone. So I opened my computer, made sure all the cables where properly plugged in - and 'lo and behold, both drives were back suddenly. :D
So don't despair. There's a reason and a solution. *grins*
well..that's what I thought...maybe it got moved.. but it doesn't seem so.
and it's only one folder that disappeared. Not a whole drive. ick...hugz I hope it'll reappear. But i need torewrite the essay. Expect email from me btw...