Here's how you can turn on telnet in Windows 8.
1. Open the Control Panel.
2. Click on Uninstall or Change a Program.
3. Click on Turn Windows Features On or Off.
4. Click on Telnet Client and Telnet Server.
5. Telnet will be installed.
6. You can then access telnet from the command prompt by typing "telnet" without the quotes.
For more, see the original article at the link below.
Enabling Telnet in Windows 8 | Tips and Tweaks