Which movie is the only one that Stephen King directed?

In 1986 Stephen King took on the task of directing "Maximum Overdrive", a movie starring Emilio Estevez. It was based on King's short story 'Trucks'. By 1986, many of King's books including 'Carrie', 'The Shining', 'The Dead Zone', and 'Cujo' had been made into films when King decided he would direct one himself.

On the CBC TV program "Midday", interviewer Katherine O'Hara wanted to know what motivated King to direct a film. He stated, "There's a spirit in writers' works, even though it's just print on the page and sometimes the director gets the sprit. I was curious, if I did it myself, what would happen? Would people say, 'you ruined it yourself,' or would they say, 'yeah, we got what we want'?"

In "Maximum Overdrive", the movie’s tone is set in the opening scene where a man (played by King) tries to take money out of an ATM, and the ATM calls him an asshole. Apparently, a comet has passed by Earth and given mechanical objects sentience. Once they attack humanity, Emilio Estevez helps lead a human resistance. The film was produced by Martha Schumacher, edited by Evan A. Lottman, and distributed by De Laurentiis Entertainment Group. It also stars Pat Hingle, Laura Harrington, and Christopher Murney.

Stephen King has called "Maximum Overdrive" the worst adaptation of any of his works, and most people don't disagree with him. Though, according to King: “I was totally drugged out of my mind all through its production and I really didn’t know what I was doing.”