Telnet is disabled in Windows by default. If you are having trouble using telnet with your Windows dedicated server it might be because you have forgotten to enable telnet in your Windows settings.
To enable the telnet client on your Windows dedicated server open the command prompt and the run the following command:
dism /online /Enable-Feature /FeatureName:TelnetClient
We always suggest that it is a good idea to re-start Windows after you make any changes to its settings, and this is also a great time to check if your dedicated server has any pending Windows updates that need to be installed.