(I'm pretty sure most of the readers of this blog know this stuff, but I'm going to say it anyway)
For one, that is a popup injected by my service provider (who is absolute garbage by the way) asking if I want help from a Micro$haft technician. I know for a fact that web browsers can send what OS you are using on the computer, so they shouldn't be asking about a Microsoft one.
The Mac by default does not BSOD. For windows 7 and higher, the BSOD has to be enabled by the user. I have only ever seen a legitimate blue screen once, and it was in my chemistry class in high school (and it was hilarious). If you don't know what a blue screen looks like, then let me enlighten you:
(This one's from Windows 95/98, but they're still pretty much the same)