you need to do the following - first answer this...
1. are you running a puter that is not directly connected to internet and is networked with one that is and it is running ICS (internet connection sahring)?
If so you are kinda screwed MSN is supposed to work with NAT (Network address translation) but I haven't had luck with it...
2. If you are directly connected to internet and running XP's firewall do the following...
-Right clik my network places
-select properties
-right clik the icon with the internet connection
-choose the advanced tab
-click settings
-click add
-for description type something like MSN file xfer 1 (you will do
this 10 times)
-for IP type the Ip of the puter that was given by ISP
-External Port: will be 6891 and TCp is selected
-Leave next field blank and hit okay
now do this 9 more times, increasing the port number by one until you get to 6900
so you will have ten of these entered, 6891, 6892, 6893... all the way to 6900
good luck, hope this helps
oh.. if u are not using XP firewall, the port numbers are still the same... the External and Internal ports will be the same number too.... and they all use TCP