UltraVNC is a powerful, easy to
use and free software that can display the screen of another computer
(via internet or network) on your own screen. The program allows you to
use your mouse and keyboard to control the other PC remotely. It means
that you can work on a remote computer, as if you were sitting in front
of it, right from your current location. If you provide computer
support, you can quickly access your customer's computers from anywhere
in the world and resolve helpdesk issues remotely !