Connection refused for Firefox. Messenger.

Ok, so my brother has had a computer since about christmas, and recently started going on the internet with it. I told him to use Firefox instead of IE, but for some reason, he gets a "connection refused when trying to connect..." message. Nothing works on the browser at all. Also, his MSM Messenger has stopped working now too, it "cannot connect" or something like that.

Any ideas? I did some searches for help on this, but i could not find anything useful, it may be something to do with a proxy, but i am not very computer savvy so i don't know what this means.
I have tried things in the Internet options, to allow these programs, but still nothing. I am at a loss with this.
Help and suggestions greatly appreciated!

Double check the network connection is operational. He may have plugged the cable into the wrong socket.
Is the account dial up or DLS / Cable?
Are there any lights on the network / modem cards when the cable is plugged in?
If he is using a dsl / cable modem, are there any lights on the modem?

If he is using a dialup connection, has he been able to plug a telephone into the wall socket to see if there is a line connection?

It is a cable connection, and it works. Internet Explorer is fine, the only things there is a problem with is Firefox and MSN. He can use IE to browse, and is able to download music, etc. It is as though some things are being allowed to work, and other flat-out rejected. His anti-virus and security is Norton, and it seems as though it is not working very well, for instance, the Live-update is not working. So i tried to delete it, but it is nowhere to be found in add/remove programs.
I have also been in the Microsoft security settings, and allowed Firefox and Messenger in that, still no joy.
It really has me at a loss!

Originally posted by PurityOfPeace
I have also been in the Microsoft security settings, and allowed Firefox and Messenger in that, still no joy.

Do you use any firewall other than Windows one?

Also, try turning off windows firewall and then launch firefox. Better way would be, disable the firewall so that it does not launch on start-up and then reboot. Then try launching firefox. This will confirm whether the problems are being caused due to the security settings of windows firewall.

Originally posted by Quake

Do you use any firewall other than Windows one?

Also, try turning off windows firewall and then launch firefox. Better way would be, disable the firewall so that it does not launch on start-up and then reboot. Then try launching firefox. This will confirm whether the problems are being caused due to the security settings of windows firewall.

He has Norton, but it is useless, and i can't get it deleted.
I have also tried turning off the Windows firewall, but i still don't get anyplace. I'm going to try it again later on maybe, so hopefully i can get some results then!