I have recently gotten in a couple of Windows 10 Professional PCs. A good guess at fixing them would be a system restore. Neither one boot. So I boot the WIndows 10 DVD and select the "System Restore" option. The first computer replied to the effect "Can't do a system restore here. You need to boot in to Windows and run it from within Windows" the one I have in here not says "This option is not supported on the operating system you've selected".
So.... how do you do a system restore on a Windows 10 computer that won't boot?