Every program and hardware driver had its own .ini file, which was a plain ASCII
text document, and each one needed configuring individually for each individual PC.
This is because there were always minor differences between PCs, such as different drive
letter or serial port assignments, so if you imported a .ini file from one Windows 3.1 PC
to another it was unlikely to work.
The Registry was Microsoft’s answer to this chaos, and it effectively pulled all these
individual .ini files together into a single, manageable database.
The Registry as we know it now was first introduced in Windows 95 and Windows
NT, and as a core component of the operating system it hasn’t changed much since. The
reason for this is compatibility with legacy hardware and software is crucial to business
users of PCs, and changing the Registry too much would either break everything, or
require a complex virtualization engine, effectively running a PC inside a PC.