Easily solve the telnet command failure failure under win7

The telnet command Telnet is a text-based program that you can use to connect to other computers over the Internet. It gives you access to programs and services on remote computers. Then if you open the Windows NT's own CMD input telnet command, the system prompts me "not internal or external commands or runnable programs or batches", how to solve it?
My first feeling is The CMD function failed, so I tried the ping command again. The strange thing is that the ping function can be used normally.
At this time, I thought that this function may not be enabled on telnet on windows7.
Open the "Control Panel", find the program and function, and then click the upper-click "open or close the windows function", the windows function dialog box will pop up, there are many small windows functions in this dialog box. , then find the Telent Client, check it and confirm it!