The early versions of Windows were basically simple Graphical User Interfaces (GUIs): they merely ran on top of MS-DOS. Windows was used merely for file system services, apart from possessing its own executable file format (Win.exe) and device drivers for things like timer, graphics, printer, mouse, keyboard and sound. The difference between Windows and MS-DOS was that Windows allowed users to execute multiple graphical applications at the same time, through what was called cooperative multitasking. In cooperative multitasking, the processor could run multiple programs in segments, whenever the CPU was not used completely. Thus if 3 programs were clicked, it would run the first program and as soon as the CPU load dropped, it would run the second program, and so on. This made all programs run significantly faster, during multi-tasking. It was made possible by means of Windows' elaborate system of software-based Virtual Memory, which allowed programs that were larger than the physical memory of the system to run too, since it allowed swapping memory in and out of the Virtual Memory (also called Page Memory) on the Hard Disk. This system, with major advances, is followed even today by Microsoft for its Windows Operating System!
Cooperative Multitasking was of course much slower than true Multi-threaded Multitasking, since Multi-threaded Multitasking allows the CPU to run multiple applications in parallel! However, true multitasking requires an expensive RISC Processor (such as that in Mini Computers) and that cost money! All said and done, Cooperative Multitasking was still a giant leap over MS-DOS, in which you had to CLOSE an application, if you needed to run a second one!
Windows 3.0 was released in 1990 and Windows 3.1 two years later, in 1992. These editions improved the way Virtual Memory was used, while allowing drivers to be loaded virtually and be shared by arbitrary devices between multi-tasked Windows Programs. Thus, you could use a single Printer virtual driver to print pages from say both Word as well as Excel, if both programs were running windowed on the same Computer. Windows 3.0 and Windows 3.1 were 16-bit Operating Systems. The next release of Windows, called Windows 3.11 or Windows for Workgroups, released in 1994, was a 32-bit Operating System.
Around this time, Microsoft decided to break away from the earlier version-based naming system and took up the year of release for naming their Windows product. Thus Windows 95, a further improvement of the the 32-bit Windows 3.11 Operating System, was released in 1995. Windows 95 also sported a brand-new User Interface. Perhaps more importantly, it broke the shackles of MS-DOS's 8.3 file naming system: you could now name your son's birthday photograph as "My Son blowing out the Birthday Candles on his 7th Birthday.BMP", instead of "Brthdy01.BMP"! Windows 95 also introduced "Plug and Play", where hardware could be plugged in and Windows 95 would recognize it correctly, without having to reboot. Unfortunately, new hardware seldom worked the way Microsoft intended it to, under Windows 95. The "Plug and Play" feature was thus ridiculed by Microsoft detractors as "Plug and Pray"! Windows 95 also used what was named "Preemptive Multitasking", where each 32-bit application had its own address space to run in. With Preemptive Multitasking, a single crashed application did not bring down the entire Computer - you could kill the crashed application alone and life would continue! Preemptive Multitasking was thus a major improvement over Cooperative Multi-tasking. Windows 95 has several versions with different versions of Internet Explorer. However, the name Windows 95 was retained.
The next Windows Release was Windows 98, released in 1998. A second version of Windows 98, called Windows 98 Second Edition was released a year later.
In 2000, with the "Millennium Bug" fears at its highest, Microsoft once again changed their naming convention. Windows Millennium (or simply, Windows ME), was the next release of Windows. It used the same core as Windows 98, while adopting a few aspects from Windows 2000, the server operating system released earlier by Microsoft, in 2000. Also removed was the option to "Boot in DOS Mode", thus making Windows a GUI-only Operating System, a full 19 years after it was first conceived! For the first time, Microsoft also introduced the now-familiar "System Restore" function into Windows ME, which allowed users to reset the Computer's settings back to an earlier date, in case of a Virus attack. However, Windows ME had to be quickly discontinued, for it had severe security issues.
At this point of time, Microsoft moved to combine their consumer and business operating systems into one entity. The result was Windows XP, with the Home edition being for consumers and the Professional edition for businesses. Both Windows XP Home and Windows XP Professional were released mid-year in 2001. Windows Server 2003, Microsoft's new server operating system, was released in 2003. It served to bring Windows 2003 up to date with Windows XP. Meanwhile, Windows XP continued to slowly build up market and mind share, but in the process, began to look old - Apple continued with their snazzy OS Improvements, bringing out sleeker and still sleeker Operating Systems. The LINUX space was buzzing with activity as well, with a number of LINUX operating systems and a number of neat-looking LINUX Desktops making an entry around this time.
Meanwhile, Microsoft was finding it increasingly difficult to deliver newer editions of Operating Systems as per initial promise. Windows Vista was released nearly 2 years after its first-announced release date, being finally released late in 2006. When it was finally released, it did not sport many of the promised features either. Consequently, public perception set in that Vista was a 'curtailed edition', leading to very slow adoption rates. Even with Microsoft stopping support for Windows XP (thus egging the public to adopt Windows Vista), sales in the replacement market did not improve significantly. Sales in the Original Equipment Market (OEM) naturally rose to 100% of Vista, for copies of Windows XP were no longer available for Computer manufacturers to bundle with their new Notebooks or Desktops with!
All these heartaches were happening at a time when a new and more powerful, feature-rich Windows should have been developed, what with Apple and LINUX bringing out beautiful, feature-rich Operating Systems. The late development of Windows Vista definitely harmed Microsoft! Windows Vista's Server counterpart, Windows Server 2008, was released early in 2008. This is why Microsoft are in a hurry to release a GREAT Operating system at the earliest!
Windows 3.0, 3.1 and 3.11 (Windows for Workgroups), along with Windows 95, were the most successful releases of Windows. This, along with the fact of Windows Vista's significant lack of success, is believed to have prompted Microsoft to go back to their earliest (and perceived-to-be more successful) naming convention. Windows 7 would have been the seventh edition of Windows, if Microsoft had continued the same naming scheme, provided you ignore the failed edition, Windows ME!
So much for superstition. Microsoft, not one to leave things to fate, also did the unprecedented: for the first time ever, they released a Public Beta of the Windows Operating System, when they released Windows 7 Beta and put it up on their website for the public to download! Initially, Microsoft had announced that the first 200,000 visitors alone would be able to download for free, a copy of Windows 7 Beta. However, public interest (and outcries too!) forced them to drop this idea. In any case, the download was taken off the Microsoft website sometime after, only for them to find that the Beta version was being freely distributed the world over! On May 5, 2009, Microsoft put up an enhanced version named Windows 7 Release Candidate on their website, for free public download. This time around, there are no rules, except that the Release Candidate will stop functioning on June 1, 2010. Before that, beginning March 1, 2010, your Windows 7 RC-running PC will begin shutting down every two hours. Windows will notify you two weeks before the bi-hourly shutdowns start!
