All Programs Disappeared

So, I'm on Home Premium, and today everything was working just fine. After one reboot, nearly all the icons on my desktop were blank. As in, the individual icon pictures were just default. Every program I try to open all pops up with "Such and such file has been moved or Deleted". The only thing I can get to work are Malwarebytes, Avira and Internet Explorer so far that I can find.

No viruses have been detected by either of the scans and I just have no idea what to do from here. All MP3 files are also useless due to every media player that I have now appearing missing including WMP, Winamp, ITunes and such.

I really have no idea what to do here. The last thing I'd want is to have to format the computer. I have one 4gig thumb drive to back up some things, but that's about all I have. If those files aren't corrupted as well. I have no way of opening them to see.

If you could help as soon as possible, I would really appreciate it.

I know I am probably not providing all the information that I can, but if you need any more, please let me know. I'll be monitoring this thread all day.

Edit: When running programs manually, I keep coming up with "Cannot run .ini or something to that effect if that helps.