I've tried three times to install Windows 10 from downloaded Windows 10 iso file using the Parallels 15 "upgrade to Windows 10" command. The Windows 10 installation proceeds through all steps to the point where Win 10 is displayed, apparently fully functional within a Installation Assistant window, whose "progress" wheel continues to spin. Under the Parallels Desktop 15 Installation menu the only available options are Suspend, Stop..., and Continue Manually... Suspend does just that. Reactivating Window 10 reopens the Installation Assistant window with its wheel spinning. Stop deletes the Windows 10 VM. Manually warns that you had better know what you are doing to proceed. I don't know how to proceed beyond this point. Looking for suggestions.