Hi wb,
After a bit of digging on the Asus website, I have found where this utility is officially listed. Try:
https://www.asus.com/Motherboards/Z170M-E-D3/HelpDesk_Download/
Select OS = "Windows 8.1 64bit" then look under "Utilities" for "ASUS Fast Boot WOL Driver V1.0 for Windows 8.1 64bit." (right at the bottom of the list)
I note that this utility has not been listed if OS = "Windows 10 64bit" is selected.
I hope this helps,
theduck01