are your friends playing it at your house on a LAN? or is the firewall blocking you at one of your houses? if the rest of the network can survive being cut off for the few hours you play, you could probably directly connect the internet to your computer, and restart it. it should get a new ip if not you could open up the cmd prompt(type 'cmd' in "Run..", in the start menu), then type: ipconfig /release ipconfig /renew try hosting the game, and having your friend connect to the IP shown on the cmd screen as for me, i'm trying to get it to work on a LAN where both computers are connected by the router and its firewall. trying to search for an answer atm
