Strange home networking issue

[Phew]

I have Adelphia cable service and two routers, a Linksys and D-link wireless g. The problem is the same regardless of which router I use. When my desktop is off, the laptop's internet connection works fine. As soon as the desktop gets to the XP logon screen, the laptop drops its connection. The connection on the desktop says 'connected', but it won't receive any packets. Turning off the desktop and restarting the router and repairing the connection on the laptop restores the connection for the laptop.

Windows Firewall is turned off on both computers. I am using the onboard ethernet adapter on the DFI NF4-Ultra D for the desktop, and Nvidia Firewall is set to 'Antihacking only'. THREE network connections show up on the desktop; 1394, Marvell, and another one called Nvidia Network adapter or something. I tried every combination of disabling connections, and the problem persists.

Does anyone know what the problem could be? This all started when I installed the new Nvidia Nforce4 drivers, but I changed alot of other things at the same time so I don't know for sure if its the new drivers. I could install the old ones again, but the computer had BSOD crashes all the time with the old drivers, so thats not really an option.

Thanks

 

[Sp33d]

Try going into the router settings with any computer. There should be a setting for the maximum allowed users on at one time. Why don't you ditch the nvidia firewall completely and get a software firewall? The antihacking mode may prevent 2 computers from getting on the same network, because it prevents you from sharing files.

 

[Phew]

I disabled the Nvidia firewall on the desktop, and checked the router settings: max users was 50, I made it 5. DHCP is enabled on the router and both computers. Problem persists.

 

[Phew]

Any other ideas?

Thanks

 

[Paperlantern]

check to make sure there arent any "bridged" connections in either the laptops or the desktops network connections screens, those wreak havoc on net connectivity under NORMAL circumstances. if all connections are single only, and look kosher, the only other idea i would suggest is blowing away the driver and network of the desktop and laptop and let the computer rebuild them, see if that works

 

[Phew]

I'm still stuck. I uninstalled every network adapter and reinstalled them. There are no bridged connections. Still, the desktop computer says it is connected, but it won't receive any packets (sends thousands of them just fine). Repairing the connection fails because it can't get an IP address. I can't reinstall windows, because windows install hangs on 'Setup is inspecting your computer's hardware configuration'. I've been without internet on the desktop for over a week now, and I'm running out of things to try...

 

[jmagg]

Try disabling the onboard nic and firewall in bios, and try a pci nic?

If you find the device thats causing windows install to hang, you'll probably find your problem.

 

[Phew]

According the DFI Street forums, the windows install hang can be fixed with a BIOS reflash (the mobo is very picky about memory, and new BIOS supposedly fixes this). I fixed the problem though:

The DFI mobo has two onboard network adapters. An Nvidia one and a Marvell one. I had been using the Nvidia one. Switching to the Marvell fixed my problem. I would use the PCI NIC, but I have no idea what brand it is, so I don't know what drivers to install. Inspecting the chips on the NIC gives no clues.