An entire generation has now grown up with Microsoft Windows, and there's a good chance it will survive another generation as well.
Windows had humble beginnings as a graphical extension to DOS, but it has changed the face of the whole industry. It liberated the personal computer market from the iron grip of the industry's biggest monopolist, IBM. It also united the home and business computer markets, which were previously on different paths, and it helped unite the desktop and server markets.
Today, Windows runs on everything from netbooks to supercomputers at prices from about $250 to $25 million. It's not dominant everywhere, of course, but it has “exceeded expectations”, which were close to zero. When the first version appeared in November 1985, providing a simple calendar, card index file, notepad and clock, surely no one suspected that some large companies would eventually use it to run most of their operations.
But it has changed a lot. Windows 3, the first successful version, launched in 1990, simply added a mouse-operated graphical user interface to the ubiquitous 16-bit MS DOS. It didn’t become a proper operating system until 1995, when Windows 95 appeared, providing support for 32-bit multitasking. Where DOS had been limited to the single megabyte of address space provided by the IBM PC’s Intel 8088 processor, Windows applications could access 2GB of virtual memory.
For a generation raised on 16K and 48K Spectrum home computers, 2GB was unimaginable.
Windows 95 was a huge success, and more or less ended the desktop aspirations of rivals such as Digital Research's GEM, IBM's OS/2, and the odd dozen varieties of Unix. It also made life extremely difficult for Microsoft’s own advanced operating system, Windows NT (New Technology). Everybody knew that NT was better. However, the mass market was driven by a combination of Windows 95’s low price, the need to run the flood of Windows 95 applications, and the PC industry’s adoption of Windows 95 as the thing to pre-install on new PCs.
When people had bought PCs running DOS or Windows 3, they could simply ignore Windows, or run it when they felt like it. Or they could run a rival graphical interface such as Quarterdeck’s DesqView or DR’s GEM.
Once they’d bought PCs running Windows 95, then switching to an alternative basically meant installing a whole new operating system, whether that was Unix, OS/2 or NT. Geeks do that kind of thing, but ordinary users don’t.
Microsoft tried various ploys to promote NT, such as offering it to PC makers at the same price as Windows 95/98, or offering big discounts if they could sell a certain proportion of NT systems. Nothing worked.
However, Microsoft did benefit, because it marketed NT as a workstation and low-end server operating system instead. (At the time, Windows was designed to sell for $40-50 whereas OS/2 and NT initially cost $400-$500, and Unix could easily cost $1,000.)