Problem with internet browsers

[Dertt]

So randomly yesterday, Firefox suddenly lost its ability to access the internet.
I checked the connection settings, they were all in place. I checked Windows Firewall, and Firefox was still on the exceptions list. To be certain, I deleted and re-added it. It continued not working.
I reinstalled the program. It didn't work.
I downloaded and installed an earlier version. Didn't work.

Internet Explorer worked, obviously.

I decided to try an experiment.

I downloaded and installed Opera. It couldn't access the internet, either. 
I checked the connection settings, they were all in place. I checked Windows Firewall, and Opera was alreadyl on the exceptions list. To be certain, I deleted and re-added it. It continued not working.
I reinstalled the program. It didn't work.

Today, in Firefox, I went to about:config and disabled IPv6, as suggested by Mozilla themselves.
Didn't work.

Soooooooooo...
Is there anything I could possibly be overlooking which would disallow all browsers other than IE to access the internet?

[Falcon]

What OS are you using? Either way that's a wierd error.

[Dertt]

XP.

[firerain]

Hmm.. Windows Firewall is an utter piece of shit. My suggestions is go grab Comodo Firewall Pro and allow Firefox and Opera. Comodo solved my connection problems.

[Sophist]

Use Safari ?_?


This is more likely than not a problem with your actual internet, not the browser.