I can’t browse on Firefox or Chrome, but can with IE 8

I am using an HP Laptop with Vista Home Premium. I just removed Privoxy and have set all browsers to no longer use a proxy. I am using McAfee Security Center with Firewall turned off and Windows Firewall turned on. I can browse with IE 8 but get no connection to any website on Firefox and Chrome. I can ping to other sites no problem.

Additionally, I am not able to ping my laptop from any of my desktops and I don’t see them on the network map on the laptop.

Thanks for the help!