Did really anything support protected memory back then?
I also am still much more bought into the power of marketing and generally focusing on getting things into student's hands as the power move that Microsoft pulled off. Probably helped a ton by a lot of failed vendors along the way. It isn't that DOS and Windows were pure successes. Rather, they managed to outsource a ton of their failures onto other companies.
> focusing on getting things into student's hands as the power move that Microsoft pulled off
That's a huge part of Microsoft's success. They looked the other way regarding "piracy" to gain market share. At least in my country nobody paid for Windows at home. If students and home users had been forced to pay, the adoption of new Windows versions would fall drastically.
OS/2 1.x supported memory protection for apps targeted for OS/2. Since 1.x was written for the 286, it put all MS-DOS apps in the same address space, so one errant app could bring down the whole MS-DOS subsystem. It would take OS/2 2.0 to exploit the 386's Virtual 8086 mode, which allowed each MS-DOS app to run isolated.
I also am still much more bought into the power of marketing and generally focusing on getting things into student's hands as the power move that Microsoft pulled off. Probably helped a ton by a lot of failed vendors along the way. It isn't that DOS and Windows were pure successes. Rather, they managed to outsource a ton of their failures onto other companies.