Windows 2000

Windows 2000 is an operating system for use on both client and server computers. It was produced by Microsoft and released to manufacturing on December 15, 1999 and launched to retail on February 17, 2000. It is the successor to Windows NT 4.0, and is the last version of Microsoft Windows to display the "Windows NT" designation. It is succeeded by Windows XP (released in October 2001) and Windows Server 2003 (released in April 2003). During development, Windows 2000 was known as Windows NT 5.0.

Four editions of Windows 2000 were released: Professional, Server, Advanced Server, and Datacenter Server; the latter was both released to manufacturing and launched months after the other editions. While each edition of Windows 2000 was targeted at a different market, they shared a core set of features, including many system utilities such as the Microsoft Management Console and standard system administration applications.

Support for people with disabilities was improved over Windows NT 4.0 with a number of new assistive technologies, and Microsoft increased support for different languages and locale information.

2000

2000 (MM) was a century leap year starting on Saturday (dominical letter BA) of the Gregorian calendar, the 2000th year of the Common Era (CE) and Anno Domini (AD) designations, the 1000th and last year of the 2nd millennium, the 100th and last year of the 20th century, and the 1st year of the 2000s decade.

2000 was designated as:

Popular culture holds the year 2000 as the first year of the 21st century and the 3rd millennium due to a tendency of grouping the years according to decimal values, as if year zero were counted. According to the Gregorian Calendar, these distinctions fall to the year 2001 because the 1st century was retroactively said to start with year AD 1. Since the calendar does not have year zero, its first millennium spanned from years 1 to 1000 inclusively and its second millennium from years 1001 to 2000 (See more at Millennium).

The year 2000 is sometimes abbreviated as "Y2K" (the "Y" stands for "year", and the "K" stands for "kilo" which means "thousand"). The year 2000 was the subject of Y2K concerns, which are fears that computers would not shift from 1999 to 2000 correctly. However, by the end of 1999, many companies had already converted to new, or upgraded, existing software. Some even obtained Y2K certification. As a result of massive effort, relatively few problems occurred.

Microsoft Windows

Microsoft Windows (or simply Windows) is a metafamily of graphical operating systems developed, marketed, and sold by Microsoft. It consists of several families of operating systems, each of which cater to a certain sector of the computing industry. Active Windows families include Windows NT, Windows Embedded and Windows Phone; these may encompass subfamilies, e.g. Windows Embedded Compact (Windows CE) or Windows Server. Defunct Windows families include Windows 9x and Windows Mobile.

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). Microsoft Windows came to dominate the world's personal computer market with over 90% market share, overtaking Mac OS, which had been introduced in 1984. However, since 2012, because of the massive growth of smartphones, Windows sells less than Android, which became the most popular operating system in 2014, when counting all of the computing platforms each operating system runs on; in 2014, the number of Windows devices sold were less than 25% of Android devices sold. However, comparisons across different markets are not fully relevant; and for personal computers, Windows is still the most popular operating system.