Current Versions:
https://technet.microsoft.com/en-us/windows/release-info.aspx
For a USB Stick:
dism /Get-WimInfo /WimFile:H:\sources\install.esd /index:1
For a PC:
in the run box type:
winver
References: http://winaero.com/blog/how-to-see-which-build-and-edition-of-windows-10-the-iso-file-contains/