I am using the Asus P4P800 non/deluxe but they are basically the same except for the IDE RAID controller on the deluxe. I use windows 2000 and have never had any of the problems you are facing. However, I would check in the BIOS whether the onboard LAN adapter is set on auto, enabled or disabled. You should set it to enabled. If all does not go well, you can reformat and reinstall windows or another operating system. Usually reinstalling windows helps. Windows is usually the source of most errors.