Back in the Windows 3.1 and earlier, install the new hardware is a nightmare. Each expansion slot must be setup manually, so you have to learn complex technical issues about how the PC actually works. If there is a problem, then the card might not work or, worse, a few other items of hardware stops working, and you must re-configure it as well.
Fortunately, Microsoft realizes it is a situation that is unacceptable, especially if they want to sell PCs to regular home users, and Windows 95 is the first appearance of their solution: Plug and Play....
