Remember the slippery slope I first mentioned when Microsoft started adding advertisements to Windows 8? Well, it’s back. And better than ever.

Or, worse. I guess.

“Earlier today, Microsoft pushed a promotional message to early adopters of Windows 11,” EdgeDeflector creator Daniel Aleksandersen explains. “The promo intended to promote the upcoming operating system’s integration with Microsoft Teams. Instead, it caused Explorer (the Windows desktop shell) to stop responding and left users without a working Start menu and taskbar.”

As you may have seen, Microsoft posted fixes for this problem, for the Windows Insider Preview Dev and Beta channels, respectively, after many users complained about the rampant unreliability. What it didn’t explain, of course, was that the instability was self-inflicted. And that it was triggered by a goddamn advertisement.

“[Before the fix was released,] Microsoft customers on Twitter and Reddit quickly shared ways to work around the problem and restore the Windows shell,” Aleksandersen continues. The successful ideas all involved different methods that made the device unable to communicate with Microsoft servers. It became clear that the issue was caused by one of the many cloud services built into Windows.”

As Aleksandersen explains, the problem wasn’t caused by an update delivered through Windows Update, it was caused by a small file downloaded by a Windows component called IrisService that is part of Windows Spotlight, which provides the Bing wallpaper of the day and various lock screen suggests that all have a Bing back-end. More specifically, it was caused by an advertisement for Microsoft Teams.

“How could Microsoft have let this happen?” he wonders aloud. “Yes, this is a beta build for early adopters. Yes, rough edges and productivity losses are expected. However, that doesn’t answer why the Windows shell was so poorly architected in the first place. How come that it would stop responding just because of one failed cloud service? It’s not a crucial cloud service either, and the computer became useless because of a single … advertisement.”

How indeed.

Windows 11 will ship to customers globally in less than five weeks. But this advertising nonsense has been present in Windows for almost ten years, and I have yet to hear a single valid argument about why. All it does is annoy users. And now, make their PCs less reliable too. Fantastic.