Finding the Windows 10 ISO version or Build Number is important because builds starting in November 2015 and newer allow you to clean install Windows 10 if you have Windows 7 or Windows 8.
- -mount the ISO to expose the files. This can be done through Windows 10, if you have another computer available or through VirtualCD.
- -find where the "install.wim" (or install.esd) is. For example; F:\sources\install.wim
- -open CMD
- -type: dism /Get-WimInfo /WimFile:F:\sources\install.wim /index:1
- -or if Windows 10 install.esd file, type: dism /Get-WimInfo /WimFile:F:\sources\install.esd /index:1
This will show the details of the INSTALL.WIM file.
NOTE:
-in some cases, Windows-7 will not be able to read a Windows-10 install.esd file :-(