IE7 Opera Firefox will not open sites

[ojas25]

Using XP Home non of the installed browsers will open any web site. I have done the following - repaired windows - run sfc scan now - run IE6 fix- run CCleaner- run winstock. Anyone have any ideas other than format. By the way the computer is will connect to the net by cable or wireless. As I have other computers connected to the router and they all connect. I would to read any answers. By the way IE8 has not being downloaded.  Ojas

[Carbon Dudeoxide]

How do you know you are connected to the internet?

Go to Star --> All Programs --> Accessories --> Command Prompt.
Type ping www.google.com and press Enter.

What are the results?

[patio]

Are you running a firewall on this machine ? ?
List ALL of your protection apps here...