Cant play Lan Battles

Hello,
Me and my friend wanted to play Rome Vanilla and EB yesterday. Unfortunatly neither worked.
When I tried to join his games my pc went incredibly slow and after like 2 minuits it said couldnt connect. Now if my friend wanted to join my matches it said after like 20second, couldnt connect to Host. We have Vista and tried everything. We unlocked the Windows defender block we reinstalled it into other folders etc.
I have read about this problem in soo many forums, but nobody has an answer. Maybe in the forum here?:dizzy2::dizzy2:

I think that might be the antivirus.
Check the settings of it.
The antivirus can deny connections and access to programs.
But I advice you to leave your firewall active: with those hackers around ... :stars:
also look if into hamachi appears blue arrow, that means you have a problem with the gates of the network.

Windows Vista !!!!!!!!! :wall::wall::wall:
I know and I change it with XP.:yes: