Yeah, that start menu area (not sure what the real name is) has panels (I bet they have a real name too) for games and junk. Not to mention how the OS is really pushing people to only use the MSFT Chromium (aka Edge) browser now, similar to how it used to push IE. I'd call that an ad as well, though not exactly what you might think of an ad.

In my experience, ads appeared in the start menu as well as ad notifications on occasion. I removed the ads from the start menu but after an update some of them seemed to return. Similar experience with the ads in the notifications tab. Although a minor experience to re-disable the ads, it was enough to get me to switch. I paid good money for windows, only to get MORE ads than the free alternative

>> are there intrusive ads in the Windows OS? If so, what kind of ads and when/where?

https://www.windowslatest.com/2021/05/30/microsoft-edge-nagg...

By default, yes. I always quickly follow the instructions online to disable all of that on a new install so I've never encountered them. For me it's no more hassle than the things I need to do on a fresh Linux install.

I haven't seen it push for Edge, in fact I don't think I've opened Edge since install day.

Windows 10 has adverts in your start menu by default

running windows 11 - no intrusive ads in the windows OS. Not sure what malware these people have on their computer.