crap.. if i were at home it'd be easier for me to walk you through it.. as i have both msn messenger and netmeeting..
i think if you go ahead and click on that ms internet directory.. and see what happens.. you should be able to register it through there.. all you'll have to do is give some personal info.. and maybe what part of the world/country you're in.. etc... and i think it will give you a list of servers.. i think...
then after you're setup on the server.. you can place calls and what not by ip address..
as for the messenger.. i'm not real sure man... sorry.