Windows 2012, Windows 2012 R2

1. Open Server Manager
2. Click on Add roles and features on Dashboard page

3. Next the wizard prompts you to verify the prerequisites have been met, click next

4. In next window Select Role-based or feature-based installation, and then click Next

5. Next check Select a server from the server pool, choose the server (the default is local server) and then click next

6. Next click on Features on the navigation pane and check Telnet Client under Features (scroll through the list to locate Telnet Client)

7. Next review the selected option and click install to start the installation process

8. Restart the server to complete the installation