MS was mainly known for its languages and its apps, more than the OS. IBM PCs still came with CP/M or PCDOS (MSDOS).
Then when Windows 3 came out, MS started to act like IBM but on steroids, thinking they owned the "stack" (as it was). OS/2 was the last attempt to extract the "PC compatible" world from the Windows domination.
Then IE6 and ActiveX ensconced MS in the enterprise. What used to be "you won't get fired for buying IBM" became "you won't get fired for buying MS because there's no choice".
The onset of the web and competitors in MS's dominant space (well except for apps, Office still rules the world) and the demise of the Ballmer years (especially the death of their mobile/phone ecology) means that MS is now actually doing what IBM did about 15 years ago when they adopted Linux.
To quote Vonnegut, "So it goes".