generally, how can I block windows (live)messenger using an individual firewall for a small computer group. TCP port? IP address? web contents? Could anybody please give some general suggestion or web link. Thank you.

I'm not really understand this.
When I use TCP port to block Windows messenger. One of the port messenger used is 443 and I can not block it. for address blocking, there should be sevral addreses for MSN messenger. If I try to block the contents from web, it seems don't work for messenger. thanks for your help.

if you read this http://www.electrictoolbox.com/arti... and block the ports it says to open it should work (the link is help to open ports to get msn messenger to work) so you would think if you block them it should work let me know

or i can make it easier for you. this is part of the article "MSN requires TCP ports 1863 and 443 open for outbound connections through your firewall" so try and block those ports.

thank you very much for your quick reply.
this is the problem I faced. I don't think I can block tcp port 443. Even EI online report does need this port for https.

i would try 1863 then

I mean after I close 1863, messenger can still connect through 443. If I stop both of them, some application are also stopped.

HERE TRY THIS

Problem:

The most widely used messenger in many locations is MSN Messenger. Therein lies the program:

If you block the main port that it uses (1683) using a firewall, MSN is smart enough to send data on port 80 (the standard HTTP port). So how do you stop all that chatting?

Answer:

1. In the registry, navigate to: \HKUR\Software\Microsoft\MessengerService\

2. Find the item named Server: messenger.hotmail.com;64.4.13.50:1863. Change this value to Null;0.0.0.0:0

That's it. Combine this with a program that can perform this change, put it on a force run, and No More Chatting!
Other Suggestions

thank you very much and i'm going to try it.