How do I install telnet on windows 10 (Not enable, actually install)

Windows ordinary repairs are unlikely to find things you removed.

(A) Try: DISM and restart.

(1) Open cmd.exe with Run as Administrator. (2) DISM.exe /Online /Cleanup-image /StartComponentCleanup (3) DISM.exe /Online /Cleanup-Image /Restorehealth (4) SFC /SCANNOW (5) Restart when all the above is complete and test.

(B) Then, if that does not work, try installing Telnet with Power Shell.

Install Telnet

Perform the following steps to install Telnet Client on a server running Windows Server Core.

 1. Type Start PowerShell in the Command Prompt window to start Windows PowerShell.

 2. Type Install-WindowsFeature Telnet-Client and press Enter to install the Telnet Client .

(C) If all fails, try a third party Telnet app. I like and use Net Term.