I am currently running Windows 8 (downloaded from DreamSpark) on a Macbook Pro. This worked fine for a while but suddenly all audio stopped working. When I go to "Playback devices" and hit "Test" on the speakers I get treated with the following message:

This also shows up right after I try restarting. I tried disallowing exclusive usage of the devices but it makes no difference.

Edit: After some looking around I tried changing the sample rate and bit depth so I would get a dialog screen to force Windows to go around the program that's using it. I did get the dialog but then instead of changing it I got the following error:

Edit 2: I narrowed it down to a single service failing to start, the Multimedia Class Scheduler service fails to start with the following error: