32-bit Operating Systems
IBM's OS/2 Warp operating system was the first to really take advantage of the processors 32-bit protected mode operation, but Microsoft's Windows 95 that was the first mainstream operating system to use it. Microsoft was originally a joint developer of OS/2 Warp with IBM until the companies split their partnership. MS went on to create and market new versions of Windows which were met with great success, while OS/2 was quietly released and forgotten.
With the release of Windows 95, something new truly occurred in consumer computing. The Intel 386, the first 32-bit processor had been released nearly 10 years earlier, and it took that long to develop a true, mainstream 32-bit protected mode operating system that was able to harness the power of that processor, and fully exploit the RAM. Up until this point, only specific software programs took advantage of protected mode, including some of the more advanced games of the time. Long time users will remember a small program called "DOS4GW.EXE", this program was responsible for switching the processor to protected mode operation while maintaining all current real mode operations, then when the application finished running, the system could switch back to real mode operation.
Windows 95 not only looked very different, but it also operated in a radically different manner than the Windows 3.x that consumers were used to until that time. Real mode was still very important, because the system has to start in real mode before switching to protected mode operation. Windows 95 has been plagued with stability problems due to its weak control of system memory. Considering the massive amounts of different hardware and software on the market, Windows 95 had to be designed with compatibility in mind, and stability was sacrificed for compatibility. This didn't sate the general public, who came up with several colorful euphemisms for Windows 95.
While Windows 95 was designed for the consumer, WindowsNT 4.0 was designed for the business world. Microsoft created an incredibly stable operating environment through the use of a radically different memory control scheme. Microsoft sacrificed compatibility, and excluded Plug and Play technology. Microsoft has continued to make stability and compatibility improvements in newer releases of the Windows family of operating systems. Several alternative operating systems have been around for roughly as long as the Windows family, but none have managed to capture a significant amount of market share.