A fresh install of windows is about as clean as you can get with driver installs.
Uninstall all items that start with Nvidia in the Control Panel (Nvidia driver first), then reboot (you may have to reboot a couple of times).
Use Driver Sweeper to get the last of any Nvidia remnants uninstalled, reboot.
Do a clean install of Nvidia drivers.
That's the surest way of getting clean drivers on there.
I try to install the 285 drivers later.