See http://kb.mozillazine.org/Firewalls

I have already removed Firefox and re-allowed it twice in Windows firewall, which is the only firewall I use, and this has not solved the problem. Thanks for the reply though.

Forgot to mention the online version of the Flash Player Installer is now affected as well. I could not update flash player using it and had to download the offline installer.

This makes me wonder whether it still is a firewall or even a router issue, but like I said I tried the re-adding as an exception in the firewall method and having not changed anything with my router I don't see why that would be an issue.

• Try this.
• Type in the address bar about:config.
• Accept the warning.
• In the page that appears, in the Filter box, type network.http.max-connections.
• Change the value to 32 (which is probably set to 256 in your case).
• Close the about:config page.
• Restart the browser.

Nope that didn't work either. Still unable to establish a connection. Appreciate the help though.

Could this have anything to do with Java or Microsoft .NET as I have plugins of those that have been disabled due to incompatability.

Oh and I also can't download flashplayer through IE when trying to watch a flash video in IE. No idea if this is related as I have not used IE on this computer in many years and is the first time I have used this version of IE on it.

Then try a clean install. Export your bookmarks to a html file and save the add-ons page for reference. Then use a free program like revo uninstaller to remove the present ff completely (the directories, registries etc.). Download FF afresh and install it. You may still have to do the fix I posted above.

I feared that may be the next step although to be fair is fairly straight forward. I will give that a go. Thanks very much!

Completely uninstalled Firefox using Revo and then reinstalled. Didn't work.

Again tried changing the max connections in about:config. Still didn't work.

Anymore suggestions? Has the latest version of Firefox changed any ports? The only thing I can think is left is something to do with my router.

Tools>Options>Advanced>Network

In Connection Settings, enable use 'system proxy settings' and see what happens.