Microsoft is a monopoly, because approximately ninety percent of all personal computers use some version of the Windows operating system. (Kaz) Furthermore, Microsoft has threatened to deny providers access to the Windows operating system, if they use a browser other than Internet Explorer. Also, Microsoft has tied it's browser, Internet Explorer, to the Windows operating system (Sandberg). While there are other operating systems available to the public, including Mac OS, Linux, Caldera, Solaris, BeOS, and OS/2 Warp, none of these are as available as Windows, and over half of them require installing them yourself, a difficult procedure for a first time user.

The results of this are that it limits the choices of the consumer, and keeps prices high. Also, it is unsupportive of new products and innovation. However, there are some positives of Microsoft being a monopoly. For example, all windows products are compatible with windows, and it is easier to keep it that way, if there are fewer operating systems to make the program compatable with.