You anymore . Retail sales for the software officially ended in October 2013, and pre-installed versions on new computers were discontinued by October 2016.

Sites like ProductSoft and SoftState often list digital keys (ESD) or physical boxes. :

If you purchase a new PC with or Windows 10 Pro , you may have "downgrade rights" that allow you to use a Windows 7 Pro license legally, provided you have your own installation media. Important Considerations License Types :