Vista - Realtek LAN Driver disappears?

My computer is fairly new with Windows Vista. For the most part, it has been running ok so far on my computer. But when I try to install some windows updates for my Realtek RTL8168C(P)8111C(P) Family. The PCI-E GBE NIC (onboard) just disappears after a reboot or a shutdown. I also have tried disabling the power management and the driver still "disappeared" in Device Manager. Now,I can no longer connect to the Internet. Please help!