I've been using windows 7 happily for months but today I noticed that I wasn't getting a network connection on my ethernet card. I looked at the back of my machine and the lights on my network card were off so I checked the router and the cable was still plugged in. I restarted my computer and went into the bios to check the network connection and the bios diagnostics were able to ping my router and transmit and receive data. The lights on the card were on. I exited the BIOS let the computer boot all the way into windows 7 but when it fully booted the lights on the ethernet card went out and windows was telling me that there wasn't a ethernet card. Only my Wifi adapter... I am really puzzled as to what would have caused this problem, any help will be greatly appreciated.