Which operating system debuted in 1985 that significantly impacted the PC market?

The operating system that debuted in 1985 and had a profound impact on the personal computer market is Windows. Introduced by Microsoft, Windows brought along a user-friendly graphical interface that made computing more accessible to a broader audience. Prior to Windows, most operating systems relied heavily on command-line interfaces, which could be challenging for the average user.

Windows' introduction fundamentally changed the way people interacted with computers, emphasizing usability and visual appeal through windows, icons, and menus. This shift helped to popularize personal computing, leading to widespread adoption by businesses and consumers alike. The success of Windows also played a crucial role in establishing Microsoft as a dominant force in the software industry and set the stage for subsequent innovations and versions of Windows that would further shape computing.

In contrast, while Linux, Mac OS, and Unix were significant operating systems, they either debuted earlier (like Unix) or were less influential in changing the personal computing landscape at that time compared to Windows.