The network adapter information below is not an Intel device, so my guess is that is the information on the built-in network connection.
The Intel® PRO/1000 GT Desktop Adapter is supported through a driver that comes with Windows 7. There is no Windows 7 driver available for that adapter that you can download. I suspect that Windows is not seeing the Intel® PRO/1000 GT Desktop Adapter at all. I am not sure why you are having this trouble, but I can think of some things for you to try.
Because you are having trouble with the built-in Ethernet connection, you should disable that connection in your BIOS. Maybe keeping the built-in connection enabled is causing you some trouble in using the Intel® PRO/1000 GT Desktop Adapter. You should not have to disable the built-in connection to use the Intel® PRO/1000 GT Desktop Adapter, but I think you should try it anyway.
Try installing the Intel® PRO/1000 GT Desktop Adapter in a different slot to see if the adapter gets detected.
Of course, there is always the possibility that you purchased a defective adapter. If nothing else works, I would return the adapter to where you bought it for a refund.
I hope this information is helpful.