Here is how to download Windows 10 14328 ESD/ISO files

Earlier this week Microsoft released Windows 10 14316 to PC Flight which brought wide new features:
  • New Windows Ink feature 
  •  New Start Menu
  • You can now set Taskbar to auto-hide in Tablet Mode
  • Improvements to Cortana-
  • You can now use Cortana on Lock Screen
  • Improvements to Action Center and Notifications
  • Action Center icon on Taskbar is now shown after the clock
  • UI changes in Action Center-Badges of unread things
  • You can now add, remove and re-arrange Quick Actions in Action Center using Settings app
  • Improvements to Taskbar
  • Taskbar settings have been moved to Settings app -> System -> Taskbar section
  • Improvements to Volume fly-out
  • Improvements and UI changes in Settings app
  • Improvements to Lock Screen
  • Improvements and UI changes in Credentials and UAC dialog box
  • Updated File Explorer icon
  • Updated Shutdown Windows dialog to use a modern icon
  • Improvements to Japanese IME
Credits:
As ISO’s of fast ring are not provided by Microsoft officially, but you can convert your Installation media file-called .ESD file to an ISO format using a software.

OPTION #1-Download ESD and decryptor

Prominent hacker WZOR has already put up the links of ESD’s on his website:
  1. Download ESD FILES FROM HERE
  2. Download decryptor from here
Convert ESD into an ISO and run an Inplace upgrade/clean Install to get to 14328.

The advantage of this method is that ESD is somewhat less size than the ISO.Typically less around ~400 MB