EZ Flash is what I used on my Asus motherboards and honestly, I prefer that to using whatever Windows based utility they provide. In the past, those were known for potentially bricking Asus mobos.
ASUS series100 motherboards can be updated with Kaby Lake support through a BIOS update, using either a USB drive in the UEFI, or within Windows. You can get the new BIOS update on the ASUS website.