Yahoo messenger and Windows Live Messenger wont connect on Vista

Hi, Im using Windows Vista Basic, and I am not able to connect to yahoo with
Yahoo Messenger, or MSN messenger (Windows Live)]

However I am able to connect with Trillan. I doubt it's a firewall
problem.. But Windows live messenger connection problem diagnostics shows a
problem with the "Key Ports" Saying my firewall might be blocking the
connection.

Trillian won't even connect with windows live.. I don't know how to open
port 1863, I've already allowed it with windows firewall

Im using an Acer asipire 5050 computer with Windows Vista Basic, 1024 RAM
80gig drive (Laptop)

I don't know if this computer has an additional firewall on it that I dont
know about, I am not running through a router, and I have another computer
that yahoo or msn works with, so its not my ISP.

Thanks for any help! :)