Is it onboard or a pci or something? But yeah, there could be many things you could try first. Such as running a hijack this, winsock fix, or checking that your network card hasnt been disabled(but you can't seem to see it, so not completly sure on that one).
The Rig: Specs
e8500 @ 4.1Ghz, 4Gb OCZ Reapers @ 1152Mhz, Gainward HD 4850 GPU, Asus P5Q-PRO, Corsair 60gb Force Series SSD, Seagate 7200.11 320Gb, Corsair 620W Modular PSU, Vista Home Premium 64