Okay found the driver on the asus website, though it should be the one you already have we need to go ahead and download and reinstall it for the moment.
ASUSTeK Computer Inc. - Notebooks - ASUS G60J
You need to choose win 7 64 then expand the lan by clicking the tiny plus sign, and download and reinstall that driver.
Hopefully the g60j is using the same lan driver, the install will simply fail if not so it's not a huge worry.
This could also be caused by a third party firewall or antivirus interfering with the device though.