Final answer:
Microsoft Windows is widely chosen for its compatibility with business software, leading to its dominant market position. Legal challenges like antitrust lawsuits highlighted unfair competition concerns, yet Windows' ecosystem's compatibility and market share perpetuate its use.
Step-by-step explanation:
Many users select Microsoft Windows as their operating system due to its high compatibility and shareability with software commonly used in business. The pervasive use of Windows has historically given it a dominant position in the market. For instance, the integration of Internet Explorer as the default web browser led to antitrust lawsuits, arguing that Microsoft's market share constituted unfair competition. Despite such legal challenges, the reality is that most business software, including databases, spreadsheets, and office suites like Microsoft Office, are optimized for use with Windows. This ecosystem encourages users to maintain up-to-date Windows versions for compatibility, especially since new software versions may not work with older operating systems due to upward-only compatibility.
Competing operating systems, such as the various UNIX versions developed by Sun Microsystems and IBM, offered proprietary solutions that were less accessible to the consumer market. The ubiquity of Windows in business computing is such that, by 2013, over 90% of personal computers sold were running a Windows system. Even though there have been initiatives to provide free and open resources in computing, commercial solutions like Windows have remained dominant due to expansive software compatibilities and market penetration.