Let me start off by saying that while I'm quite familiar with the Windows Operating System, I'm also somewhat contemptuous of it (the famous quote definitely applies, here!).
This is because of its well-known tendency to become unstable and "crash". Your computer becomes useless until you re-boot it.
However! Today I happened to think of a situation where this is desirable! Let me now change the subject to "nanotechnology"....
In science fiction (useful for making people think about things that might go wrong, so that those things could be prevented), nanotechnology is sometimes portrayed as getting out of control, and converting everything on Earth into a big mass of something known as "gray goo". End of civilization. End of humanity, too. Not nice!
But!
The individual elements of nanotechnology are sometimes called "nannites", and despite their size, they are a variety of computer hardware, and they therefore will need an Operating System.
That's where Windows can save the world. Before the nannites can get out of control, they will crash! Hooray!-- Vernon, Mar 15 2011 Another way to save the world from nannites http://www.xkcd.com/865/FYI. [Vernon, Mar 15 2011] Yes, but then someone would bring out the iNannite and we'd be back in the hist.-- MaxwellBuchanan, Mar 15 2011 Windows is what's holding off the Martian invasion, don't you know? Yep, they too have seen War of the Worlds, which ironically lead them to call of their attack.
No Microsoft product would ever be able to take over the world... oh... wait...-- RayfordSteele, Mar 16 2011 random, halfbakery