You do not need to Activate Windows 10 to install it, but this is how you can activate later. Microsoft has done an interesting thing with Windows 10. Besides giving it as a free upgrade to anyone with an activated Windows 7 or Windows 8 PC the OS is also one big shareware demo.

Can I use Windows 10 Pro without activation?

Microsoft allows anyone to download Windows 10 for free and install it without a product key. It’ll keep working for the foreseeable future, with only a few small cosmetic restrictions.

What happens if Windows 10 Pro is not activated?

When it comes to functionality, you won’t be able to personalize the desktop background, window title bar, taskbar, and Start color, change the theme, customize Start, taskbar, and lock screen. However, you can set a new desktop background from the File Explorer without activating Windows 10.