Mozilla and Opera disabled

Oh, that's nice -- Mozilla and Opera cannot connect to anything and even a .NET HttpWebRequest fails; IE works on http connections, but not https. But, I can connect to secure sites from within a VMWare session!

Sigh. I've deleted my network adapter and it got automatically re-installed when I rebooted, but the problems continue.

When I run a .NET HttpWebRequest on my own domain, the exception I get is the nonsensical

Unhandled Exception: System.Net.WebException: The underlying connection was clos
 ed: Unable to connect to the remote server. ---> System.Net.Sockets.SocketExcept
 ion: No connection could be made because the target machine actively refused it
    at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Sock
 et s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state,
 IAsyncResult asyncResult, DecrementTimer timer, Exception& exception)

I have a feeling this is going to suck big time...