Windows 10 Anniversary update is some hours away, but thanks to Pastebin, we have got the ESD files of Windows 10 build 14393 which you can easily use to Convert to an ISO.Windows update uses ESD files for download. I am providing the links for EN-US 64 and 32 bits both, you can get the rest from the Pastebin link
Download
Follow this article to convert the ESD(Electronic service delivery file) into an Installation media:
Get the Installation media file before the upgrade for future purposes in Windows 10
Then follow this to update when you have successfully created an ISO:
