History

Microsoft is a multinational company operating in the field of computer technology and software development. Its headquarters are located in Redmond, Washington, United States. It was founded by Bill Gates and Paul Allen in 1975.

Fig. 1.1. Paul Allen (left) and Bill Gates (right) founding Microsoft in 1975

The first version of the MS-DOS operating system was released in August 1981, and the graphical interface Windows 1.0 on November 20, 1985. The first version of the popular Microsoft Office productivity suite was released on November 19, 1990.

Fig. 1.2. Microsoft Windows 1.0 released in 1983

Fig. 1.3. Microsoft Word 1.0 released in 1989

The Windows 8 and 8.1 operating systems were introduced on August 1, 2012 and August 27, 2013 respectively. Support for Windows 8 and 8.1 ended on January 12, 2016 and January 10, 2023 respectively. The latest major release of the widely used desktop operating system, Windows 10, was released on July 15, 2015.

Fig. 1.4. Windows 8.1 released in 2013

Fig. 1.5. Windows 10 released in 2015

According to official figures published by Microsoft, installations of Windows 10 and 11 for the period from 2015 to 2025 are shown in Table 1.

Month and year	Number of devices
July 2015	Windows 10 launch
September 2016	400 million (Windows 10)
March 2017	500 million (Windows 10)
September 2018	700 million (Windows 10)
March 2020	1 billion (Windows 10)
October 2021	Windows 11 launch
October 2023	400 million (Windows 11)
April 2022	1.4 billion (total Windows 10 and 11)
July 2025	Windows 11 – 52% market share, Windows 10 – 44.59%

Table 1 Installations of the Windows 10 and 11 operating systems

According to official figures published by Microsoft, the public releases of the Windows 10 operating system are shown in Table 2.

Version	Build	Release
1507	10240	July 2015
1511	10586	November 2015
1607	14393	August 2016
1703	15063	April 2017
1709	16299	October 2017
1803	17134	April 2018
1809	17763	October 2018
1903	18362	May 2019
1909	18363	November 2019
2004	19041	May 2020
20H2	19042	October 2020
21H1	19043	May 2021
21H2	19044	November 2021
22H2	19045	October 2022

Table 2 Public releases of the Windows 10 operating system

More information about Windows 10 releases can be found online at: https://docs.microsoft.com/en-us/windows/release-health/release-information/

According to official figures published by Microsoft, the public releases of the Windows 11 operating system are shown in Table 3.

Version	Build	Release
21H2	22000	October 2021
22H2	22621	September 2022
23H2	22631	October 2023
24H2	26100	October 2024
25H2	26200	September 2025

Table 3 Public releases of the Windows 11 operating system

More information about Windows 11 releases can be found online at: https://learn.microsoft.com/en-us/windows/release-health/windows11-release-information