Try checking your motherboard manufacturer's website to see if they have newer drivers available. Also, check to see if the drivers are WHQL Logo'd.
I have WinXP Pro w SP2. Norton Internet Security 06, and M'soft Antispyware Beta1. I am switching Cable providers and need to go back onto dial up for a few days. I have tried to "disable" my LAN connection by going thru the icon in my Lower right system tray, plus have tried to disable thru Device Manager to Network Adapter and disable there. Each time I click disable,my PC does an immediate self restart and upon returning to desktop, an error message comes up saying your computer has just survived a major correction and do you want to notify M'soft. I have a mobo with NVidia chipset. NVIDIA nForce Network Controller. Any other suggestions? I have a laptop running Win XP and have no trouble disabling LAN connection thru "disable" when click on icon in system tray there. Thanks, Jim