I got it to work without format my windows. Just exited my AVG, and it worked, started up AVG and it didnt. So I tried to troubleshoot, and found the problem was in the "web shield" on AVG, just unclick "Instant Messaging protection". Tried to solve this problem before, but it was problably because I unchecked only msn messenger, and not the other one. Hope this solve the problem for you.