You can try booting up a linux based OS. Like Ubuntu 9.10 it has the option to try it without a change to your pc. I suggest trying the network card with a cable then and if it doesn't work it is a hardware problem. Many Linux OS supports trying them without really installing them on the HDD. You can also try hiren's boot cd and boot mini windows xp but I don't think it supports many drivers for network controllers. best bet is ubuntu/Fedora/Suse because they have plenty of drivers.