FYI, my clean install went well; however, I did encounter a strange bump in the process that I cannot explain. Here's what happened:
1. Checked my recovery folder for the presence of the install.esd file. It was not there, I had the install.wim (same as davidhk129).
(Note: I did have the folder options set to show hidden files and unhide protected operating system files)
2. On a hunch, I did an explorer search for "esd" (without quotes), and guess what, it found the install.esd in the same location as the install.wim file.
3. So, I opened the recovery folder and NOW the install.esd file was there and the install.wim file was gone? (note davehc's comment about them both being the same size).
4. Can't explain how or why this happened but I took a chance and processed the newly found install.esd as follows:
5. Downloaded ESD Decrypter from here, ran it and selected option 4.
http://winaero.com/blog/get-iso-image-for-windows-10-build-9860-for-a-clean-install/
6. About 30 minutes later, I had my ISO (processing time will vary here).
7. Download Rufus and ran it to convert my ISO to a bootable USB drive (left all options at default).
8. Once done, did a clean install of build 9860; all went well.
For the record, I did a clean install of the first Win 10 download and then upgraded to build 9860 initially. How or why my install.wim file was changed to an install.esd file by doing a simple explorer search is beyond me?