Microsoft has released a new update build 10586 of Windows 10 to Windows Insiders in the fast ring which comes with many bug fixes and improvements. This new build comes via “TH2” (ThresHold2) development branch.
You may download the previous Windows 10 Insider Preview (x86) – Build 10565 and let Windows Update download it. When Windows Update has prepared the upgrade, you will be told a restart has been scheduled. At this point you can find the install.esd file which contains everything needed to make an ISO image in a hidden folder C:\$Windows.~BT\Sources.
Click here for “esd-decrypter-wimlib-4.7z” and used it to convert .esd format to. iso format.