Microsoft veteran Raymond Chen has shed light on the mysterious setup process of Windows 95, revealing it was actually three programs chained together. The process varied depending on whether a user started in MS-DOS or ran from Windows 3.1.
The initial program, which Chen describes as a “mini-Windows 3.1,” loaded if the user began installation from MS-DOS. This stripped-down version of Windows performed basic tasks like gathering user input and detecting hardware before transitioning to the next stage.
In contrast, running from Windows 3.1 launched a 16-bit Windows app that handled the majority of the installation work, including file copying, driver installation, and setting migration. The final program, a 32-bit Windows app, completed any remaining tasks before booting into the actual operating system.
Chen’s explanation underscores the complexity of the setup process, which relied on a single set of code executed from different starting points. This revelation revisits an era when minimal versions of Windows could run from floppy disks, highlighting the significant strides made in computing over nearly three decades.
Source: https://www.theregister.com/2024/11/19/chen_windows_95_setup