Telnet is a protocol that allows you to connect remote computer over tcp/ip network. By Telnet client software on your system that helps you to make a connection to telnet server.
Port used for telnet is 23 .
Here is demo how to use telnet command with port number.
Now Enable Telnet Client , Go to program and features then look for turn windows features on or off,
Check telnet client and press Ok ,
After Clicking Okay ,
It will ask you for restart the system ,
Press restart now , you have enabled telnet client now.