When accessing some internet sites I keep getting HTTP Error 500 how do I fix?
HTTP error status 5xx are server errors. Unless you administer these systems, you shouldn't bother about fixing them. You may want to report them to the admins, though.
One exception is that if you've configured a proxy server, this may cause trouble as the proxy server will return 5xx error status codes when it runs into problems itself. Try to disable a proxy if you're using one.