Vista - Internet Problems

I am new to the site and found this on a question that I googled. Here's the question: I am able to connect to the internet via internet explorer but unable to connect through any other browser or program that requires or is able to connect to the net why is that?

I remeber all of a sudden after I updated my itunes I couldn't connect to my account but then all of a sudden an update came for Firefox and I wasn't able to connect with that one as well so out of curiousity I checked random stuff such as AIM and Win Media Player and nothing. I even tried to connect to AIM on Explorer and nothing.

I did cut everything off firewalls and such and nothing I checked my connection settings for firefox just to see if I could at least get backon with that and nothing. I even tried to mirror the settings on Explorer to Firefox and nothing.

I would definitely appreciate any help at this point not that I wouldn't any other time but right now it's sort of frustrating because I love Firefox and I've got some Itunes cards from Christmas I'm anxious to use!

Thanks to everyone in advance!