9151 is the ControlPort, not the SocksPort. The SocksPort is still 9150. Unable to resolve server is a DNS resolving error. There is a way around this using Tor's mapaddress functionality. Shut down TBB. Open the Tor configuration file with a text editor. On Windows, it should be in Data\Tor\torrc, wherever you extracted your browser bundle. Add this to the end of torrc: mapaddress 192.0.2.2 silcroadg3c3mtu6.onion Start the browser bundle. Go to mIRC and enter 192.0.2.2 for server instead of the onion address. Edit: Port 9150, not 9050