Windows 11’s latest optional update – which is a preview of Moment 3 (KB5026446) – is causing trouble for some users, coming with some bugs, and worse still, in some reported cases the upgrade is installing itself automatically.

Windows Latest reports that it experienced the installation of KB5026446 going ahead automatically when updates were checked for on the PC. Note that as an optional update, one that might contain gremlins in the works (which it apparently does), the user should have to manually trigger the update.

In other words, you should have to choose to install this preview update, it should not be installing automatically.

Windows Latest observes that it has received reports from readers that this unexpected installation of KB5026446 has occurred, and indeed, elsewhere online we’ve seen other reports of this happening (even, in some cases, if people hadn’t checked for updates).

As for the problems the Moment 3 preview update is causing, there are various reports of diverse issues, as you might expect with a patch still in testing. One of those is that it breaks the Microsoft Store, or messes with the Game Pass on PC (making games unplayable, we’re told).

There are other reports of worrying system freezes, some apps failing to open, and the keyboards and mice of some users failing to work post-update.

There were installation failures too, with the usual meaningless error messages (strings of hexadecimal), but that’s pretty much par for the course these days it seems with Windows 11.

Analysis: The clue is in the name – ‘optional’

The good news, well, such as it is, is that in all these cases, simply uninstalling the update (via Windows Update, under Update History) cured the PCs of the various ailments mentioned. The galling bit here is for the folks who didn’t want to install the optional update in the first place, of course.

How widespread is this issue with the KB5026446 preview update installing itself? It’s difficult to say, but it is certainly happening for a number of folks. Windows Latest does observe that if you do check for updates, and notice it installing, if you hit ‘Pause Updates’ that’ll cancel the installation. So that’s worth bearing in mind.

One theory is that this sneaky installation may be tied in to those who have selected the new option in Windows 11 to ‘Get the latest updates as soon as they’re available’ (and using that is necessary to enable Moment 3’s new features in KB5026446, as Bleeping Computer previously made clear).

However, even if you have selected this choice, you should not be getting an optional update piped through with no warning at all (especially when you haven’t even checked for updates, as seems to be happening in some cases). Optional updates should always be exactly that – an option, not an automatic installation (and certainly not one occuring stealthily behind the scenes, as it were).

Hopefully we’ll hear from Microsoft soon enough to clarify what’s going on here.