Story time: There was another operating system very much like Windows called OS/2. This operating system was made by IBM and Microsoft. It even had DOS and NT kernel compatibility and is where the NT kernel came from. While MS and IBM were working on OS/2 MS secretly developed Windows and made deals with third-party PC manufacturers like HP and Compaq for them to run Windows and not OS/2. Despite the fact that Microsoft was where it was then because IBM had chosen DOS for its PC operating system until that time.

OS/2 still got an interesting life though. It was widely used as an embedded operating system well into the 2000s. If you ever used an ATM or cash register in the early 2000s you almost certainly used OS/2.

Windows did not get where it is today through organic growth. It did so by standing on the shoulders of giants and dealing under the table.