Microsoft really started on its course toward great fortune and power when Windows 1.01 arrived in 1985. Since then, Microsoft and Windows have been indivisibly intertwined.
There were indeed earlier prototype versions of Windows, and there were lots of other graphical user interfaces, including those from Apple, Atari, Quarterdeck and IBM. But Windows propelled Microsoft to become the largest personal computer software vendor, a record setter in market capitalization at $618 billion in 1999 that made billionaires by the batch.
That's not bad for a product that was so late to market that it made the term "vaporware" a permanent part of the technology dictionary because it took so many tries before Microsoft got it right.
When PC Week started in 1984, the tagline read, "The News Weekly for IBM System Microcomputers." The lead story was about graphics being added to an IBM 3270 PC, a PC that was designed to emulate a 3270 mainframe terminal. There was no mention of Microsoft, no mention of Apple and reading that first regular PC Week issue you'd think it was all about IBM—which mostly it was.
The history of Windows also traces the rise and fall of the love affair between Microsoft and IBM. The two companies were close in the early PC-DOS days. But the relationship turned frosty when it became clear that Microsoft was seizing control of the PC operating system market with MS-DOS and later Windows.
It finally ended with a bitter divorce in 1991 when IBM introduced the OS/2 PC operating system in a failed attempt to assert its independence from Microsoft in the enterprise market.
That history is also replete with early clashes between Apple and Microsoft over similarities between Windows and the Mac interface that were difficult to dismiss as happenstance.
Although it's sometimes forgotten, the rise of Windows was also about the rise of high-tech marketing, where it was possible to build up interest in a product that wouldn't reach the market in a usable form for years. But Microsoft was able to use its marketing machine to influence the influencers and get consumers demanding Windows even though they had no idea what they were asking for.
Here is a brief history of the major Windows releases from my perspective. Windows 1.01 was essentially a front end to the MS-DOS operating system. That command prompt never really disappeared in subsequent releases, but the difficulty of tacking Windows onto DOS meant for a buggy ride. Those bugs were not really (mostly) squashed until Windows 3.1 in 1992.