Enabling Telnet in Windows 7 and Vista.

1. Open Control Panel.
2. Open Programs .
3. Open Programs and Features.
4. Click the link Turn Windows features on or off.
5. A small window will open with a list of features put a tick for  Telnet Client.
6. Click OK button.
7. You can now start telnet from command prompt.

This trick is useful for networking students.