Where I can download VNC
How to use a web browser as a viewer - need port 5800+
How can I make the VNC server connect to a client, instead of the other way around
“This server does not have a valid password enabled. Until a password is set, incoming connections cannot be accepted"
Unable to connect to host: Connection refused (10061)
Java.net ConnectException: connection Refused
Which port does VNC use

Where I can download VNC

VNC stands for Virtual Network Computing. It is, in essence, a remote display system which allows you to view a computing 'desktop' environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures by using an Internet browser. To download VNC, search it in the Internet (http://www.uk.research.att.com/vnc/index.html).

How to use a web browser as a viewer - need port 5800+

You can remote control a computer by using web browser. To do that, you need use port 5800 or up (for example, http://computername:5800) and enable Java viewer.

How can I make the VNC server connect to a client, instead of the other way around?

Occasionally it is more convenient to have the server make the connection to a client; if the server has a dynamic IP, this may be the only way to do it. Here's the process. Let's say we have a machine at address 192.168.1.1, Client1, which wants to "take over" Server1.
 
(1) Start VncViewer on Client1 with the "-listen" switch, like:

vncviewer -listen

(2) On Server1, make sure that WinVNC is running as a service if possible; it needs to be running already for this to work.  If not, then she just starts it the normal way.  Make sure it's already started before going to Step 3.
 
(3) On Server1 you just run Winvnc with the "-connect" option. If Server1 is typically used only to connect to Client1, you may want to make a shortcut something like this:

"C:\Program Files\ORL\VNC\Winvnc.exe" -connect 192.168.1.1

“This server does not have a valid password enabled. Until a password is set, incoming connections cannot be accepted"

If you get above error message when attempting to access a VNC host, re-logon or reboot the VNC host and apply a password.

?java.net.NoRouteToHostException: Operation: time out.