Telnet is available for Windows 7, but it is not installed by default. This was the same for Windows Vista. Microsoft removed the Telnet client for security reasons. Whenever you have the choice you should use SSH instead of Telnet.
However, you can re-enable the Telnet client in Windows 7 by doing the following:
- Control Panel
- Programs And Features
- Turn Windows features on or off
- Check Telnet Client
- Hit OK
After that you can start Telnet via Command Prompt.