Telnet is a protocol that enables you to connect to remote computers and local computers over a TCP/IP network, over TCP port 23. By default in Windows 10 and 8, Telnet is disabled in recent Windows environments.
To enable Telnet command line utilities: Click Start > Control Panel. Click Programs and Features
Open and Windows 10 Telnet
Here is quick how to open Windows 10 Telnet
2. Click Turn Windows Features on or off