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It’s hard to remember how the world of computers was before the introduction of Microsoft Windows. On Nov. 20, 1985, Microsoft announced a new idea for MS-DOS computers, a graphical interface that would let people use computers without having to type in commands. That idea was Windows, but it wasn’t much like the Windows you’re used to today.
I’d actually heard about the advent of Windows a few days before. I was writing for Byte magazine in those days and occasionally freelancing for a new publication called PCWeek, and we’d had the heads-up from the Microsoft public relations staff. When Windows arrived, it came on two floppy disks.
In those days, there were several different flavors of MS-DOS computers. When you ran an application, one of the first things you did was tell an installation program what kind of computer you had so the program would work with your monitor and keyboard. Nobody had a mouse that worked with MS-DOS PCs.
So, of course, I tried to run the new Windows on the first MS-DOS computer I could find, which happened to be a Zenith Data Systems Z-100. It didn’t work. Turns out that Windows would only run on MS-DOS computers that were compatible with the IBM PC. So I went to find one of those.
The first version of Windows wasn’t really an operating system. Instead, it was what Microsoft called an MS-DOS Executive. This meant that it was basically an application that ran on top of MS-DOS, and would run programs with the click of a mouse—if you were one of the few PC users who had a mouse.
Eventually, software companies began to write applications that were designed specifically to work with Windows. It took years for Windows applications to show up in large numbers, but this proved to be the beginning of a significant change in the way users worked with software.
It was really Windows 3.0/3.1x, released in the early 1990s, that made PC users convert to the Windows graphical user interface and work with a mouse. By this time, Windows programs had a consistent look and a more-or-less consistent interface. While you could run native MS-DOS programs with Windows at times, Windows programs began to look alike.
Still, at this point, Windows was still what Microsoft called an Executive. This meant that it ran in place of the MS-DOS text interface, but it still used MS-DOS to run programs. And in some cases, you could still run those programs without first running Windows. But that changed with the advent of Windows NT, which was a real operating system, not a shell for running applications.
Windows NT was the direct predecessor of today’s Windows 10. It was a stable 32-bit operating system that did not require MS-DOS to work. Instead, if you needed a DOS application, you could run it in a window. Interestingly, you can still do this by running a command called “CMD” in the run bar on your version of Windows. Those old MS-DOS commands are still there, and they still work.
Windows at 30: How Microsoft Changed the Personal Computing World
What really made Windows NT important and helped ensure that Windows would dominate the PC world was something almost nobody knew about at the time. Deep within Windows was the Hardware Abstraction Layer.
This allowed programmers to make their software work with Windows by providing the software interface to the hardware in much the same way that a computer’s BIOS provides a low-level hardware interface to the specific machine.
At this point, there was Windows for consumers and Windows for business users. But within a couple of years, Microsoft made the next critical change that would cement Windows into a place for serious computing, which happened when Windows NT became Windows 2000, and the versions of Windows based on DOS were dispatched to history.
Then came Windows XP in 2001, which is without question the most successful PC operating system ever. This was the operating system that essentially defined how personal computers could run reliably with a lot fewer of the infuriating “Blue Screen of Death” crashes that plagued earlier versions of Windows.
XP was so well done that 14 years after it first shipped, it’s still Microsoft’s most widely used operating system. It was, effectively, the default operating system for the world.
Microsoft has tried to move on from Windows XP, first with Windows Vista, then with Windows 7. Despite all of that, XP was what people ran on their computers, and it’s what runs computers today, although its installed base is gradually shrinking, whether they’re desktop machines, displays at airports or support for bank ATMs.
Windows 7 only partly replaced XP, and Windows 10 is still trying to replace Windows 7. The biggest factor in the success of Windows 7 and 10 is age, because computers with XP are simply wearing out.
By now, the total number of computers running Windows has passed 1.5 billion, according to Microsoft, although the exact number is unknown. More than 90 percent of all computers in the world run Windows, according to several estimates I’ve found. What this means is that Windows has given the world’s computer users an operating system that was easy to learn, stable and generally good enough to dramatically enhance their productivity.
“It’s remarkable to reflect on the impact of Windows over the past 30 years, and we are excited about the road ahead with Windows 10, which is already the most successful Windows ever,” a Microsoft spokesperson told me when I asked her to reflect on the past three decades in which Windows has risen to dominance.
“We’re thankful to all of our employees, partners and customers around the world for the role they play in making Windows a part of their daily lives. We look forward to many more years of empowering individuals and organizations to do more.”
What the spokesperson said about Windows being part of the daily lives of nearly everyone who uses a computer is central to the place this OS holds in the world of computing. It’s now part of life for billions of people, and that alone has profoundly affected history.