An operating system [o/s] is very important because a computer is just electronics [chips,diods, capacitors,resistors, etc, etc. ] that DON'T KNOW what to do unless told so. The o/s TELLS everything inside the computer when to do things, how to do things, where to go to do things, WHO should do things. Your program won't know how to turn on the monotor, what colors to use so that you can see properly. What language do you want to read, or hear in one language & see the words in another. The o/s must!! set up these things so that your program will work.Another thing, whats happens if you take out your program a place your buddys prlgram, the system would CRASH, because the computer was set for yours. With an o/s you can change programs as if you were changing hats!!