Does a driver exist to step up a PC USB 3.0 port to charge an iPad at 12W? The iPad Retina requires 12W to charge. 

It appears the Mac has special non-usb-standard drivers that step up the USB 3.0 port to provide the extra power for charging. 

My question is: Does a driver exist to step up a PC USB 3.0 port to charge an iPad at 12W?
Your motherboard may have a firmware update to enable it, or add-in driver on the install CD/DVD

Ref - iPad displays “Not Charging” when plugged into USB ports. What can I do?