Windows 10 will prompt you to activate it after installing[1] and updating it a bit, or after a few restarts, without any significant penalties should you fail to do so.
Windows 10 will restrict you from a few features such as logging into your Microsoft account and changing account names or such if you fail to activate it. Eventually you may be restricted from using the OS as a whole, but it seems more forgiving now than previous versions of Windows in that regard. I’ve got a machine I never activated and just wanted to run into the ground that still works fine a year later.
It still shows the “Activate Windows” watermark in the bottom right.
victorgrant replied
402 weeks ago