I was unable to use Disk Utility or Boot Camp Assistant to properly create the Windows 10 USB Flash Drive from my OS X 10.10.4 Mac as of August 2015.
iso disc image to a 4GB or larger USB Flash Drive, and this step is best done from a Windows computer. Purchase Windows 10 as a download from the Microsoft Store or Amazon. If you buy the Windows 10 Pro version it includes the installers for both the Pro and Home 64 bit versions.
Purchase Windows 10 on USB flash drive from the Microsoft Store, Amazon or a local computer reseller. Microsoft makes it easy for existing Windows 7 and 8 users to get a free version of Windows 10 from within Windows, but for a new installation of Windows on a MacBook that has never had a copy you'll want to look at the following methods:
