the server has to be installed on the pc that will be remotely controlled; you can then control that pc remotely with a web browser or with the viewer program.
With the server running (just execute server and enter password), the remote control session can be initiated in 2 different ways:
1- by entering in the viewer or browser the IP address and UVNC password of the remote pc
(in this mode if the server is behind a firewall or router, you will need to configure the firewall to accept incoming connections and the router to forward port 5800 to the local IP of the remote pc)
2- with the viewer in "Listen mode"(a special shortcut is created for this purpose during installation), the pc to be controlled can initiate the connection to the viewer by entering the viewer's IP address in "add client". This is useful if someone is at the pc to be controlled (as when remote assistance is needed).
(if the viewer pc is behind a router/firewall, you will need to forward TCP PORT 5500 to the viewer's local IP address)
If you want to access an unattended remote pc, then use the 1st option.
You have installation and setup instructions here:http://ultravnc.sour...t/install/index.html
And very useful forum:http://forum.ultravnc.net/
I have not tried LogMeIn, but as I understand it, the major advantage it has is that there are no router/firewall issues, at the expense of performance (as data travels thru central server as opposed to a direct p2p connection)