You need to use a SSH client to connect to your VPS to get a shell prompt/command prompt.
Connecting using an SSH client is encrypted and should be used instead of telnet.
A small and free SSH client is Putty and can be downloaded from http://putty.nl/
It's an exe and there is no need to install it.
When you run Putty you enter the IP address or hostname of your VPS and it will prompt your for the login (root) and password.
It defaults to using SSH which you need to use. It has the ability to save your connections.