I remember that the PC my parents got in 1996 couldn't even hold one CD of data. (~500 MB, but Encarta 95 that came with it was >600 MB) My parents were and still are cheapskates.
Yup, back in those days games required the CD in to play not because they had to check you bought the game but because the games actually required the resources on the disc.
My parents were so cheap I didn't even have encarta but some cheap IBM branded clone.