Windows

## Windows: Operating System

**Windows** is a group of several proprietary graphical operating system families, all of which are developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. Active Windows families include Windows NT and Windows IoT; these may encompass subfamilies, (e.g. Windows Server or Windows Embedded Compact) (Windows CE). Defunct Windows families include Windows 9x, Windows Mobile and Windows Phone.

Microsoft introduced an operating environment named *Windows* on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs). Windows came to dominate the world's personal computer (PC) market with over 90% market share, overtaking Mac OS, which had been introduced in 1984.

Apple came to see Windows as an unfair encroachment on their innovation in GUI development as implemented on products such as the Lisa and Macintosh (eventually settled in court in Microsoft's favor in 1993). On PCs, Windows is still the most popular operating system in all countries. However, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android, because of the massive growth in sales of Android smartphones. In 2014, the number of Windows devices sold was less than 25% that of Android devices sold. This comparison, however, may not be fully relevant, as the two operating systems traditionally target different platforms. Still, numbers for server use of Windows (that are comparable to competitors) show one third market share, similar to that for end user use.

As of October 2021, the most recent version of Windows for PCs and tablets is Windows 11, version 21H2. The most recent version for embedded devices is Windows 11, version 21H2.The most recent version for server computers is Windows Server 2022, version 21H2. A specialized version of Windows also runs on the Xbox One and Xbox Series X/S video game consoles.

## Genealogy

### By marketing role

Microsoft, the developer of Windows, has registered several trademarks, each of which denotes a family of Windows operating systems that target a specific sector of the computing industry. As of 2014, the following Windows families were being actively developed:

* Windows NT: Started as a family of operating systems with Windows NT 3.1, an operating system for server computers and workstations. It now consists of three operating system subfamilies that are released almost at the same time and share the same kernel:
	+ Windows: The operating system for mainstream personal computers and tablets. The latest version is Windows 11. The main competitor of this family is macOS by Apple for personal computers and iPadOS and Android for tablets (c.f. Usage share of operating systems § Market share by category).
	+ Windows Server: The operating system for server computers. The latest version is Windows Server 2022. Unlike its client sibling, it has adopted a strong naming scheme. The main competitor of this family is Linux. (c.f. Usage share of operating systems § Market share by category)
	+ Windows PE: A lightweight version of its Windows sibling, meant to operate as a live operating system, used for installing Windows on bare-metal computers (especially on many computers at once), recovery or troubleshooting purposes. The latest version is Windows PE 10.
* Windows IoT (previously Windows Embedded): Initially, Microsoft developed Windows CE as a general-purpose operating system for every device that was too resource-limited to be called a full-fledged computer. Eventually, however, Windows CE was renamed Windows Embedded Compact and was folded under Windows Compact trademark which also consists of Windows Embedded Industry, Windows Embedded Professional, Windows Embedded Standard, Windows Embedded Handheld and Windows Embedded Automotive.

The following Windows families are no longer being developed:

* Windows 9x: An operating system that targeted the consumer market. Discontinued because of suboptimal performance. (*PC World* called its last version, Windows Me, one of the worst products of all time.) Microsoft now caters to the consumer market with Windows NT.
* Windows Mobile: The predecessor to Windows Phone, it was a mobile phone operating system. The first version was called Pocket PC 2000; the third version, Windows Mobile 2003 is the first version to adopt the Windows Mobile trademark. The last version is Windows Mobile 6.5.
* Windows Phone: An operating system sold only to manufacturers of smartphones. The first version was Windows Phone 7, followed by Windows Phone 8, and Windows Phone 8.1. It was succeeded by Windows 10 Mobile, that is now also discontinued.