First, go to the Asus support page for the product. You'll need to specify the OS as windows 7 64 bit.http://www.asus.com/Motherboards/M5A78LMUSB3/HelpDesk_Download/
Next you will want to download:
Chipset, Audio, Lan, USB and the utilities you require, in that order.
For utilities, I recommend:
AI suite II, AIcharger, AsMedia USB 3.0 driver and the Asus EPU-4 engine. Find the most current versions for each. I can't provide a direct link to each driver and utility as the Asus page will always take you back to the OS selection prompt.