Those persistent "Get Windows 10" pop-ups are going away soon, after Microsoft's free upgrade offer for Windows 10 expires on July 29.
During those final days and hours, anyone still running Windows 7 or Windows 8.1 should brace for one last round of upgrade prods from Redmond, including a full-screen message, as the GWX program moves into its final phase.
The details are in a new Knowledge Base article, Windows 8.1 and Windows 7 SP1 end of free upgrade offer notification, which includes a screenshot of the message and some helpful hints on how to avoid seeing it more than once.
Two noteworthy additions are visible in the lower-left corner of that screen. Instead of merely dismissing the reminder, you can ask to be notified up to three more times, or you can specify that you've made up your mind and don't want any more notifications.
That "Do not notify me again" message should stop all further upgrade prompts.
You won't see this message at all if you've previously suppressed the Windows 10 upgrade using the registry modifications described here: How to block Windows 10 upgrades on your business network (and at home, too).
You'll also be spared the notification if you previously uninstalled Windows 10, had a failed installation attempt that resulted in a rollback, or your PC has been determined to be incompatible with Windows 10.
If you're still on the fence, or if you want to postpone the upgrade without incurring any extra costs, one option is to install and activate the free upgrade, then roll back to your current operating system. That action records a Windows 10 digital license for the hardware in question and allows a later upgrade. For details, see: How to lock in your free Windows 10 upgrade and keep using your old Windows version.
After July 29, upgrades to Windows 10 will be sold, not given away. The current retail price for Windows 10 Home is $120, and for Windows 10 Pro, the upgrade sticker is $200.