[Krypton]

I have a D Link ADSL modem + router connected to broadband with 4 users connected.

1 x wired ethernet (WinXP)
1 x intel centrino laptop (WinXP)
1 x Mac mini Belkin usb adapter <--- Me!
1 x PCI card (random manufacturer) with Ralink drivers WinXP

It's the latter user who is causing problems. I myself use the OS X version of the Ralink (they make the actual chipset inside) drivers, and he uses the Windows version. Everytime his computer joins the network the internet connection consistently disappears; the router still says it's connected though.

He is able to connect to the router to view its web interface, as we all are when this occurs. But no one is able to access the internet.

Any ideas? I've never experienced anything like this before, as I have the same setup at home - I'm in a shared house at Uni currently.

Any ideas and inspiration appreciated!

[ghporter]

Have you tried reloading the Windows drivers on the offending machine?

[Krypton]

We've uninstalled and reinstalled the latest version of the Ralink drivers for his PCI card, we've disabled Zone Alarm 6 as I found that it can cause problems with the Ralink driver, and I let him borrow my Belkin usb adapter and try it with Belkin's own drivers.

All to no avail.

Whenever I disable his wireless network interface and restart the router, the internet magically comes back everytime!

I even had a fourth computer (he has a laptop also) plugged into the router tp confirm the number of users wasn't an issue.

It's looking increasingly like there is something he has installed that is causing the problem, but I am still stumped.

[Krypton]

My friend has installed a fresh copy of WinXP + the drivers and all seems well.

I guess we can conclude that there was an application conflict of some sort

[John Strung]

It sounds as if the culprit maching has internet connection sharing turned on. Check the network connections on the XP machine and if there is a network connection called "bridge", delete it.

[ghporter]

Or not having chosen EITHER WinXP OR the Railink driver to control the card. Installing a vendor driver does not automatically tell XP to let that driver control the card, and XP will often try to do so-unless you explicitly tell it not to. This was why I asked if you'd reinstalled the driver, because removing the driver sometimes untangles the problem.