Windows 1.0 is the first major release of Microsoft Windows, a family of graphical operating systems for personal computers developed by Microsoft. It was first released to manufacturing in the United States on November 20, 1985, while the European version was released as Windows 1.02 in May 1986.

Its development began after the Microsoft co-founder and spearhead of Windows 1.0, Bill Gates, saw a demonstration of a similar software suite, Visi On, at COMDEX in 1982. The operating environment was showcased to the public in November 1983, although it ended up being released two years later. Windows 1.0 runs on MS-DOS, as a 16-bit shell program known as MS-DOS Executive, and it provides an environment which can run graphical programs designed for Windows, as well as existing MS-DOS software. It introduced multitasking and the use of the mouse, and various built-in programs such as Calculator, Paint, and Notepad. The operating environment does not allow its windows to overlap, and instead, the windows are tiled. Windows 1.0 also contains four releases, which contain minor updates to the system.

The system received lukewarm reviews; critics raised concerns about not fulfilling expectations, its compatibility with very little software, and its performance issues, while it has also received positive responses to Microsoft's early presentations and support from a number of hardware- and software-makers. Its last release was 1.04, and it was succeeded by Windows 2.0, which was released in December 1987. Microsoft ended its support for Windows 1.0 on December 31, 2001, making it the longest-supported one out of all versions of Windows.



Microsoft Corporation is an American multinational technology corporation which produces computer software, consumer electronics, personal computers, and related services. Its best-known software products are the Microsoft Windows line of operating systems, the Microsoft Office suite, and the Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface lineup of touchscreen personal computers. Microsoft ranked No. 21 in the 2020 Fortune 500 rankings of the largest United States corporations by total revenue; it was the world's largest software maker by revenue as of 2016. It is one of the Big Five American information technology companies, alongside Google, Amazon, Apple, and Meta.

Microsoft (the word being a portmanteau of "microcomputer software") was founded by Bill Gates and Paul Allen on April 4, 1975, to develop and sell BASIC interpreters for the Altair 8800. It rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Microsoft Windows. The company's 1986 initial public offering (IPO), and subsequent rise in its share price, created three billionaires and an estimated 12,000 millionaires among Microsoft employees. Since the 1990s, it has increasingly diversified from the operating system market and has made a number of corporate acquisitions, their largest being the acquisition of LinkedIn for $26.2 billion in December 2016, followed by their acquisition of Skype Technologies for $8.5 billion in May 2011.As of 2015, Microsoft is market-dominant in the IBM PC compatible operating system market and the office software suite market, although it has lost the majority of the overall operating system market to Android. The company also produces a wide range of other consumer and enterprise software for desktops, laptops, tabs, gadgets, and servers, including Internet search (with Bing), the digital services market (through MSN), mixed reality (HoloLens), cloud computing (Azure), and software development (Visual Studio).

Steve Ballmer replaced Gates as CEO in 2000, and later envisioned a "devices and services" strategy. This unfolded with Microsoft acquiring Danger Inc. in 2008, entering the personal computer production market for the first time in June 2012 with the launch of the Microsoft Surface line of tablet computers, and later forming Microsoft Mobile through the acquisition of Nokia's devices and services division. Since Satya Nadella took over as CEO in 2014, the company has scaled back on hardware and has instead focused on cloud computing, a move that helped the company's shares reach its highest value since December 1999.Earlier dethroned by Apple in 2010, in 2018 Microsoft reclaimed its position as the most valuable publicly traded company in the world. In April 2019, Microsoft reached the trillion-dollar market cap, becoming the third U.S. public company to be valued at over $1 trillion after Apple and Amazon respectively. As of 2020, Microsoft has the third-highest global brand valuation.