Vista - Internet stopped working.

I do not know if this has been posted before but I could not find it if it has.

After using Vista for about a year my internet stopped working. Like others I am connected to the net (my Xbox works fine) but I cannot get IE to work. I called the tech support for my cable modem and company and after troubleshooting the tech said I had a problem with my port 80.
Also mu I-tunes started saying it could not connect to the internet about 2 months ago and various other programs are now telling me the same thing.

HELP!!!!

Thanks

Port 80 refers to a web browser such as IE

Your problem sounds like a firewall issue... which one(s) do you use? Windows Firewall, Norton... Try disabling it and see if you can surf the web

I've taken down the firewall and anti-virus. Also I am able to do windows updates and they download just fine, no connectivity issues. When I open MS Money and sign in it also works fine.

I am having a similar problem and would appreciate any guidance. My IE stopped working yesterday. The message I get is "address not valid," as if I've typed an incorrect URL.

Other programs that access internet without using IE (such as Real Player) still work, and I have another computer accessing the internet in the same room, so I'm just about certain it's not a modem issue. I noticed that Microsoft downloaded into my computer a large "update" just a couple of days ago, right before the troubles began.

I've been reading posts on this forum and have followed some advice so far, but to no avail. I've...

1. Disabled all add ons.
2. Done an IE reset, to the manufacturer's original settings.
3. Tried turning off Firewall.
4. Various and sundry other matters.

This is most vexing, as my computer and the Vista program I'm using are only about 4 months old.

Thanks for any insight into how to rectify.