What happens to those free Windows 10 upgrades after July 29, 2016?

We're nearing the end of Microsoft's unprecedented free upgrade offer for Windows 10.

The offer officially expires July 29, 2016, on the one-year anniversary of the operating system's initial release. But what happens then? [Updated]

Read the ZD Net article

[This article has been significantly revised and updated since its original publication. in January 2016]