To find what version / build number of Windows 10 your installation media contains perform following steps:

• Insert the installation DVD or mount .ISO file
• Open elevated command prompt (run as administrator)
  
• Run one of the following commands:
  • dism /Get-WimInfo /WimFile:F:\sources\boot.wim /index:1
  • dism /Get-WimInfo /WimFile:F:\sources\install.esd /index:1
    Replace F: with drive letter of your DVD / ISO.
• Output will look something like this:
  
  In the above example the installation media is for Windows 10.0.10240 Build 16384, which is the first Windows 10 RTM release (Threshold 1).

December 2016