How can I take control of a users PC without changing their router or firewall rules?

Much like PC Anywhere, VNC has an option to enable a reverse connection. In VNC this is called a Listening Server. The advantage of a listening server, is that because the remote client is initiating an outbound request, most firewalls/routers, etc. will allow the connection to proceed. It also means that you do not need to know the clients IP address, they need to know yours.

1. Install VNC, I suggest RealVNC and all instructions from here on will be based on using RealVNC.
2. From the RealVNC menu -> VNC Viewer -> Run Listening VNC Viewer.
3. Add exceptions to any firewall products such as Sygate Personal Firewall or the Windows XP Firewall to allow TCP Port 5500.
4. If you are using a router, add a port forwarding entry to your LAN IP address.
5. Make note of your WAN IP address.

You machine is now ready to accept incoming control requests.

Now that you are ready to accept requests, you can have any client who has VNC installed give you acces to their machine. With VNC installed on the client machine, they need to follow these few steps:

1. Start the VNC Server.
2. Right-click on the VNC system tray icon and select Add New Client
3. Enter in your WAN IP Address, the address of the VNC listening viewer
4. Hit connect.

If all goes well you will now be able to control the clients machine and any other user you like.

If you are like me and find that getting someone to install VNC and instructing them to then click on the icon, etc... can become more trouble that it is worth. You can simplify the process even further by making a script file that runs the necessary command line to add a new client, etc.

I will leave that for another FAQ.

Dylan Thompson