Browsers intermittently stop working Windows 7 desktop

[flyinggizmo]

I've been having a problem with my Windows 7 machine for some time now. Sometimes all the browsers stop accessing internet and only way to get them back is to disconnect the wireless connection and reconnect. I have a laptop (XP) that works perfectly wirelessly as do my iphone and ipad. Also my other desktop (XP) machine is connected by ethernet cable and that works fine as well. I've tried all the suggestions I can find on the Internet to do with DNS resets etc. but I think it's pointing more towards some problem with the settings in Windows 7. Any help appreciated. Many thanks.

[Tomken]

This could either be the Network drivers or your AV.

Booting up into Safe Mode with Networking will isolate your AV to eliminate that, but it's usually best to start by updating/reinstalling the drivers from your computer vendor's support site.