I got a call from my colleague asking me that he was not able to get the Telnet command working in Windows Vista. So for all the Telnet lovers, follow the steps below to get it working:
1. From the Start menu, click Control Panel.
2. Select 'Programs and Features'
3. From the menu on your left, select 'Turn Windows Features On or Off'.
4. This would pop up a window
5. Scroll down, and then check the "Telnet client" box
6. Click OK.