If you ask a bunch of systems administrators what tools do they use when troubleshooting remote services and ports, one of the top answers would definitely be the Telnet client! Windows 7 includes a Telnet Client but it is not installed by default. However, a tool that is more flexible and powerful than Telnet Client is PortQry. This tool has been around since Windows 2000 and version 2 has more features, you can download PortqryV2.exe from Microsoft’s Download Center as it is not included with Windows 7.
Telnet Client is a useful utility that helps us determine whether remote or local network services are running and reachable from the client side. For example, to test for a service running on port 8080 on a remote host you would type telnet remote host IP 8080 from the command line. Then you act according to the command’s reply. Remember that telnet does not provide you with enough information to diagnose all network/service problems; however, it is a very handy tool! Operating systems before Windows Vista had this utility installed by default but now you have to do some extra steps as detailed below: