When Windows 95 crashed, on the next boot you'd get this blue screen with a progress indicator and a number of items with checks next to them. Scandisk. It told you what it was doing. If you didn't understand it, you at least knew that you had to wait for it to finish and roughly why.
For Windows 98, they improved this by replacing the descriptive check marked items with a berating message. "Windows was not shut down properly." You don't need to know what it's doing, just that you are its slave and you must wait.
In Windows ME, they finally realized that anything in text mode is to be avoided at all cost. Scandisk is now only a GUI application that starts after the multitasking kernel has loaded. This allows background tasks to endlessly force it to restart. (And you're not allowed to ask why.)
(Windows 2000/XP do better, they run ChkDsk while still in single task mode. Yay!)