Use for questions where the server throws 500 Internal Server Error and the server is not in your control. For servers in your control, look through the server logs to pinpoint the actual problem
The 500 Internal Server Error is a catch-all error code that can mean literally anything. Instead, look through server logs, etc and try to pinpoint the actual problem and tag it accordingly.
The relevant section of the HTTP protocol:
http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html
More information about codes returned from IIS 7:
http://support.microsoft.com/kb/943891