The internet on my computer won't connect to anything but internet explorer

[x4isCosmic]

The internet on my computer will only connect to internet explorer. It won't connect to programs like iTunes(the music store), limewire, firefox, etc. I've gone through my computer several times looking for something that might be blocking it and haven't found anything. I don't think it's a firewall, I've checked that. Of course I'm not 100% sure what I'm looking for.
And I have a cable connection if that makes a difference. (I've checked the box and it appears to be working)

[Broni]

What Windows version?

[x4isCosmic]

It's Windows XP

[Broni]

Disable your firewall for a time being, and try to use Itunes, or Limewire.

[x4isCosmic]

I already disabled it. That was pretty much the first thing I tried. I have no idea whats wrong.

[Broni]

Does your IE browse with normal speed, or it's slow? Any troubles with opening some pages?
What happens when you open Limewire, Itunes?

[x4isCosmic]

IE is running as well as it alway has.
When I try to open the itunes store it says: iTunes could not connect to the iTunes store. The network connection was refused. Make sure your network settings are correct and your network connection is active, then try again.

When I try to open limewire it says: Your machine does not appear to have an active internet connection or a firewall is blocking limewire from accessing the internet. Limewire will automatically keep trying to connect you to the network unless you select "Disconnect" from the file menu.

[Broni]

For Itunes, check if your settings are same, as here:
http://docs.info.apple.com/article.html?artnum=304468

[x4isCosmic]

Dangit, didnt work. 

[Broni]

Don't worry. We just made first step.
Did you have that setting already set to Automatic?
Do me a favor. Using IE, go to: https://webassign.net/login.html
and tell me, if IE let you go there. You don't have to read anything there. I just want to know, if you have an access to that site.

[x4isCosmic]

Nope, it wasn't already set, now it is though
The website worked too

[Broni]

OK, then...
Try Itunes now, and let me know...

[x4isCosmic]

itunes is still coming up with the same message

[Broni]

That's OK.
Next step.
Open Firefox, click Tools>Options, click Advanced, click Network tab, click Settings button.
Make sure, that you have it set to "Auto-detect...".
Restart Firefox, and see if it works.

[x4isCosmic]

I selcted the auto-detect but it still won't work.

thank you for helping me by the way!!