my engin will just die then i wait for about 15min then it will start right back up i don't know what the problem is

I was driving down the road, when all of a sudden, the engine just quit. I tried to start and it would turn over, but not start. No fire to the spark plug. A friend put it on his computer and it would not even read the computer. He feels we need to replace the computer and that will fix it.? What do you think.