original question: How many video game distribution system does [Microsoft Windows] support?
answer: 4
answer type: Video Game Distribution System.
auxiliary information: Microsoft 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 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. 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, it sells less than Android, which became the most popular operating system in 2014, when counting all of the computing platforms Windows runs on; in 2014, the number of Windows device sold were less than 25% of Android devices sold. As of July 2015, the most recent version of Windows for personal computers, tablets and smartphones is Windows 10.
What is the quantity of video game distribution systems that [Microsoft Windows] supports?