Like, can anyone give me a thumbnail of ports/protocols it uses, etc? Please go into detail as I need to block traffic through a firewall to stop it.

Are you referring to MSN messenger? If so, it can really use any port since it supports proxying. In fact, I think that messenger automatically starts searching for open ports if it has trouble connecting through the default(s).

Here's a list of registry edits you can do, though, to restrict/change messenger bahavior. I'm not sure if I completely understand your question - but I hope that helps some!

- trs

Ports 6891-6900 (6901?) are file sending . It uses 1863, 80, 1503, 3389, 5060 - but I have no idea what these are for, sorry (apart from 80, but you'll know too so no point in me saying it, or listing it for that matter, but I'm too lazy to delete it)

Messenger, and also the Webcam access. Sorry, I was not really clear there.

i believe 1863 is for webcam access. when people have trouble viewing mine i advise them to open 1863-1900 and it normally fixes it.

Can blocking happen through group policies at the Domain level(s)? At the very least you could prevent the app from running by name. That'd at least stop the punters, but not necessarily the determined folks.

-Zeke