Certain programs cannot access internet under Vista

[Bleak]

Hi,

I bought a new PC recently with Vista installed (I used XP before).

Anyways I installed my Router (Sagem F@st 1400W) on the new PC and got
internet working properly (I can access all websites through IE or Firefox).

However certain programs such as Steam or Windows Live Messenger are unable
to connect. (I tried the troubleshoot in Messenger and everything is ok, even
the key ports, yet it can't connect. I think it's error 810306 (tells me a
firewall is blocking it)

And yet I've disabled the windows firewall and any antivirus software...

Any help is welcome.

 

[Bleak]

I've used the Norton Removal Tool, unchecked IPv6 protocol, etc, but I still
haven't found a solution.