It's not enough for Windows to inform me daily how many people have upgraded to Windows 10 and how much happier I would be if I would only stop resisting and submit—reports are coming in of Windows 10 taking matters into its own hands and installing itself on Windows 7 and 8.1 systems without permission.
This Reddit thread with nigh-on 5,000 upvotes is chock full of tales of people going away from their desks and later walking in on Windows doing something it shouldn't, finding it minutes or even seconds away from an auto-update. The lazy among us will be all too familiar with being unexpectedly kicked from a game at a crucial moment as Windows restarts, the update warning having hidden behind the fullscreen application. Turning it back on to find a new operating system is another level of rage-inducing altogether.
The problem, it seems, can be traced back to a Microsoft blog post of October 29 titled 'Making it easier to upgrade to Windows 10'. Oh boy. Making it easier translates to re-categorising Windows 10 as a 'Recommended Update', causing it to download and install automatically, depending on your settings. But don't worry! According to the blog, "Before the upgrade changes the OS of your device, you will be clearly prompted to choose whether or not to continue."
That is not what many are reporting. In some instances, the OS update follows the default Windows 7 upgrade process, providing you with a 15-minute warning before it assumes consent, and that warning, as we know, is easily missed. Others claim they received no warning at all. More curious still, an experiment by Woody Leonhard for InfoWorld using a Windows 7 virtual machine found the Windows 10 update in the 'Optional' category. Unchecking it had no effect—Windows Update would re-check it each time it was run—and Windows 10 attempted to install itself anyway.
This contrasts with Microsoft's official line: "Customers continue to be fully in control of their devices, and can choose to not install the Windows 10 upgrade or remove the upgrade from Windows Update by changing the Windows Update settings."
This saga has unsettling echoes of the aggression Tim Sweeney recently cautioned against in his attack of the Universal Windows Platform. Until this gets resolved, maybe install a hidden camera to keep tabs on your computer when it thinks it's alone?