By default the TelNet client is not installed in Windows 7. You can install it by doing the following steps:

1. Click the START, then select Control Panel.

2. Select Programs and Features.

3. Select Turn Windows features on or off.

4. Check the Telnet Client checkbox.

5. Click OK.

6. A box will appear showing the installation process.

When it finishes running, the client is installed.

Thanks