On the server side, they're hovering at 30%-ish, and are almost completely absent from the start-up scene as well as the high-end super-computer space. The startup scene, which, I know, I know, but still, it is where the future is, is definitely not interested in anything MS, from what I can tell. Nothing bug a sea of MacBooks with people pounding away at Node/RoR/language-of-the-day. The hip 20-somethings pounding away at a thousand start-ups don't seem to be betting on the MS stack. And those are the tech leaders of tomorrow.
Forget about the start-up space, fine. What about other institutions like banks/finance/airlines? That's all Java, running on some kind of Unix-derivative as well, most likely hitting a non-MS database.
MS is doing ok in the video game console space, but Sony is doing better. They're doing ok with Azure, but nothing spectacular, AWS and Google Cloud and Dig. Ocean and the numerous others aren't feeling too much pressure.
I guess really besides Office - what do they have that's a giant run-away success that will ensure their long-term survival?