Drivers would be :
Motherboard (IDE controllers, USB controllers, on-board audio, wifi, IR, etc)
Any third party add-ons such as PC cards
Drivers are difficult to "back up" as such, although there are one or two utilities that claim to do it. Many devices will work using generic windows drivers but you will most likely end up with a load of triangles in device manager.
You would be far better off with the motherboard CD or download the install packs from the hardware vendor's web site.