Funny thing I discovered - and have confirmed now through research: Win10 is free to install (at least the latest 1803 is - not sure when this happened), and will work fine with all features without ever activating it. The only thing you lose is the ability to personalize the desktop (wallpaper, taskbar, etc), and you'll get an Activation nag occasionally on the desktop and in the notifications center.
So if you have some old laptop laying around you want to try Win10 on, but don't want to waste money on a license for it, just throw it on there and don't bother activating. You can also use this to install Win10 in a VM.
SECONDLY, even though the free Win10 upgrade offer is over, you can STILL ACTIVATE (PERMANENTLY!) A CLEAN INSTALL OF WIN10 using a Win 7 or 8 key. It has to be the correct version (eg: Win7 Pro key to activate Win10 Pro). It will license your motherboard so once activated, that mobo will have a Win10 license for life and will automatically activate. I just confirmed this works. I still have some unused Win7 Pro licenses around - mostly from Dell OEMs that came with Windows XP downgrades. I just activated my new gaming PC with one of them, so I guess the new license I bought will go on the shelf for some other project.
All the Ways You Can Still Upgrade to Windows 10 for FreeHere’s the real secret: You don’t need to provide a product key to install Windows 10. You can download Windows 10 installation media from Microsoft and install it on a PC, in Boot Camp on a Mac, or in a virtual machine without providing a product key. Windows will continue to work normally and you can do practically whatever you want.
Windows 10 will keep nagging you to activate it and won’t allow you to change any of the options under Settings > Personalization, but otherwise work just fine. It’s not something you’d necessarily want to do on your main computer, but it’s a very convenient way to set up a quick virtual machine, test Windows 10 on a PC, or install Windows 10 in Boot Camp. You can even pay to upgrade to a legal, activated version of Windows 10 from within your unactivated Windows 10 system after installing it.
https://www.howtogeek.com/272201/all-th ... -for-free/