Your motherboard has a Z77 Intel chipset so uses drivers for that, not nVidia. You've got the right nVidia drivers. The chipset drivers came on the CD with your motherboard or you can download them from Asus.
Yep that'd be it I have the Intel chipset drivers and on the motherboard CD they are also listed for install. I was just worried that I had accidentally uninstalled some important drivers but it would appear not.
This thread is pretty much answered now (:
Thank you zdbc13