Microsoft Windows

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Microsoft Windows is a trademark of operating system for computers. The most recent versions of the system are Microsoft Windows 10 and Windows Server 2016.

History of Windows versions

The current versions of Windows have their roots in two fundamentally different pieces of software marketed under the common name "Windows". The oldest one ("DOS-based") brought most graphical interface aspects (windows, task bar, start button...) while the other one ("NT-based") brought the underlying stability and security. A third family of Windows software is devoted to embedded and mobile devices but the latest versions of Windows Phone are now NT-based as well.

Windows on DOS

In the old days, most IBM-compatible personal computers were equipped with the operating system Microsoft DOS. IBM itself provided it as default operating system on its personal computers under the name PC-DOS. Microsoft developed Windows, a graphical user interface on top of DOS. Windows 1.0 went out in 1985. Windows 3.0 (1990) was the first popular version of Windows, with 7 million copies sold in the first year (mostly because Windows was then sold together with DOS when people bought a computer). Until Windows 3.1 (1992) and Windows for Workgroup 3.11 (which brought some networking features in 1993), one had to buy and install DOS and then Windows. Starting with Windows 95 (which came out in 1995), both layers were combined into one product. Further evolutions of this branch included Windows 98 (1998) and Windows ME (Millenium Edition, in September 2000).

Windows NT

As the hardware was evolving, IBM and Microsoft had started in 1985 to work together on a new operating system called OS/2 that would include a number of fundamental improvements and be aimed at replacing DOS. A few versions of OS/2 had been released already and a new version was being developed. Due to the success of Windows 3.0, Microsoft then decided to make the new version of OS/2 somewhat compatible with Windows, while IBM was against this idea: that's where their collaboration ended and IBM continued alone to develop OS/2 as originally intended.

Microsoft pursued its new idea of an operating system providing extended Windows capabilities instead of extended OS/2 capabilities. That became Windows NT whose first version, released in 1993, immediately bore the number 3.1. It was marketed as an operating system for professional environments, with several variants targeting workstations and servers. Windows NT 3.51 (1995) and Windows NT 4.0 (1996) had a lot of success. They were followed in February 2000 by Windows 2000 (internally known as Windows NT 5.0).

Windows on mobile devices

Windows CE is yet a different operating system created by Microsoft, designed to take as little storage space as possible. It is not based on DOS, nor on OS/2 and Windows NT. Microsoft licences it to other companies for them to create user interfaces in all kinds of electronic devices. Microsoft itself has used Windows CE to create interfaces for mobile devices such as smartphones: these versions were known as Pocket PC (released in 2000), Windows Mobile (from 2003 to 2009) and Windows Phone 7 (released in 2010).

Merge

Windows XP (internally bearing the version number 5.1) was released in 2001. It was the first version based on Windows NT intended for all end-users, for both personal and professional usages ("Home" and "Professional" editions). Thanks to its Windows NT bases, this version brings a tremendous increase in security, stability and performance to end-users in the consumer market (personal usage). A new version of Windows XP (v.5.2) came out in 2003 that supports 64-bits computer architectures. Further versions include Windows Vista (released in 2006 for professionals and 2007 for the general public, internally numbered v.6.0), Windows 7 (2009, v.6.1), Windows 8 (2012, v.6.2) and Windows 8.1, with the most current iteration being Windows 10 (2015, v.10.0/6.4).

As with previous Windows NT versions, the same code base is also used for server versions. For marketing reasons, Microsoft gave server versions other names than end-users versions. Server versions equivalent to Windows XP, Windows Vista, Windows 7, Windows 8, Windows 8.1 and Windows 10 are called respectively Windows Server 2003 (v.5.2, there is no equivalent to v.5.1), Windows Server 2008 (v.6.0), Windows Server 2008 R2 (v.6.1), Windows Server 2012 (v.6.2), Windows Server 2012 R2 (v.6.3) and Windows Server 2016.

Microsoft Windows Phone 8, released in October 2012, is the first version of Windows Phone that is based Windows NT.

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