Using Windows 3.x as the example OS would have been a more sensible choice then 95. Windows 95 is way more than a "wrap per" over DOS"! Windows 3.x had way more dependency with DOS than Windows 95 had! Windows 3.x had to offer a "collaborative" way of doing multitasking, each task had to yield to the OS in order for it to Check what any other task had to process in it's message loop, if you wanted to freeze the OS all you had to do was to not call the yield function. Windows 95 supported a preemptive scheme that wasn't there before Back then (kinda like NT did support).
Somebody forgot DESQview, it was pure DOS without any Windows.
Who can forget QEMM and the joys we had running multi-line BBS's.