Ok guys, this is, I think, my first tutorial so bear with me. Many people have been getting the Assassins Creed II Multiplayer error that basically tells you to forward UDP port 9103. I fixed mine the following way, so hopefully this fixes it for you to, if you have this problem. This is for Windows 7, but should work for Vista and I think also XP. So first you are going to want to open up Control Panel by clicking the bottom left Windows icon (START), then control panel. Then click on System and Security. Please Register or Log in to view images Click on Windows Firewall next. Please Register or Log in to view images Then advanced settings. Please Register or Log in to view images Then inbound rules on the left. Look a spot that says New Rule... Click on that. Please Register or Log in to view images Select the option that says port and hit next. Please Register or Log in to view images There should be two sections. One part says TCP or UDP. Select UDP. Then you need to select Specific local ports. Type 9103 in that same area. Then, you guessed it, click next! Please Register or Log in to view images Make sure you have Allow the connection selected (should be default) and then you should have Domain, Private, and Public all selected (I think all should be default that way). Name it something like Assassins Creed II Multiplayer or something. Then click finish and exit out of everything. You should not get that error anymore, if you do, PM me and I can try to help, but this worked for me. And let me know if it works or at least leave a response so I know I didn't do this for nothing. Add me: ElSock Good luck and hopefully have fun!