I am having a similar problem with the F5D7000, and a D-Link 530TX. When ever I have a nic card installed be it Wifi or Cable it locks my system up after it boots into windows. With out an active network connection though the system is great, it only locks up when I have an active connection. It is on a PC-Chip M577 and I have checked and rechecked IRQ settings, DMA, ect. I would love to resolve this, if it helps the rest of the Specs are Windows 98SE, AMD K6-2 350, 160mb SDRAM 10ns ram, PC-Chips M577, 36X CD-ROM. It has PCI 1.2, AGP 2X, USB 1.0, ISA, and on board Sound.

Can you clearify active network connection. Do you mean on the internet or just you LAN or both? Have you tried a different PCI slot? What makes you think it's hardware and not software related?