The process cannot access the file because it is being used by another process. (Exception from HRESULT: 0x80070020)
All of my websites on IIS7 were stopped. Whenever I tried to start any of them I would get the exception:
"The process cannot access the file because it is being used by another process. (Exception from HRESULT: 0x80070020)"
After doing some googleing I found that it was a problem with Skype. When it iwas loading on boot up it was taking port 80 before IIS could.
So I just quit Skype freeing up port 80. This allowed me to start my websites in IIS. I then restarted Skype which was smart enough to take a different port since 80 was already taken.
Hopefully this helps someone else.