How long can you use Windows 10 without activating it?
Here's a Jewish answer: Why buy Windows if you can run it for free? In short, the answer is forever (until further notice...).
Many computers are sold without Windows in order to reduce prices. You can download and install Windows 10 without any problems WITHOUT ACTIVATING IT. Microsoft is still providing updates for unactivated copies of Windows 10. When prompted for the product key, click on the "Skip for now" button.
"Here is the list of limitations you will face in this situation:
A watermark [a notice - AR] will remain at the lower right-hand corner saying Activate Windows.
Windows will send out notifications asking you to activate Windows....
There will be a ‘Windows isn’t activated, Activate Windows now‘ notification in Settings.
You will not be able to change the wallpaper, accent colors, themes, lock screen, and so on. Anything related to Personalization will be grayed out or not accessible.
Some apps and features will stop working.
Although currently, you may still get Updates, Microsoft is likely to change its policy in the future."