Mark your calendars, Windows people. July 29 is the release date. Here’s the important part:

Windows 10 will be free for users who have bought a computer in the past six years or so, powered by Windows 7 or later, or tablets running Windows 8.1.

There you go.

I went ahead and reserved a copy (I’m running Windows 7 on an HP Pavilion Slimline that I bought four years ago). Microsoft says

When you reserve, you can confirm your device is compatible with Windows 10. Between reservation and when your upgrade is ready, the files you need for the upgrade will be downloaded to your PC to make the final installation go more quickly. Then, when your upgrade is ready after July 29, 2015, you get a notification that lets you get started with your upgrade.

So download all you like, Microsoft, but I don’t have to actually press the button to start the installation until I’m ready to (which might not be until after Service Pack 1 for Windows 10 comes out down the line sometime). I can live with that.