The telnet command is disabled by default in Windows 7. You can easily enable the telnet client using the following steps:
1. Open the Windows 7 Control Panel (Start > Control Panel)
2. Click on the “Programs” link.
3. Under the “Programs and Features” setting, click on “Turn Windows features on or off” link.
4. Tick the “Telnet Client” selection box. Wait for Windows 7 to install and enable the selected feature.
5. Done! You should now be able to run the “telnet” command on the Windows 7 command prompt.