(FORTUNE Small Business) – HURLING MY TYPEWRITER down a flight of stairs was, I'm freely admitting two decades later, a shortsighted move on my part. Not because I committed a ridiculously childish act; in fact, all it took was a few strong bounces to unstick the balky "e" key that had triggered my wrath. No, my failing was that my fury blinded me to a business opportunity. Right then I should have vowed to become the first mover in what now ranks among the fastest-growing entrepreneurial niches: exploiting the epidemic called computer rage by helping hotheads fix the source of (or clean up after) their tantrums.

In other words, I wish I'd had the foresight of Ken Smith. "Digi-rage has absolutely fueled the growth of the in-home IT business," says Smith, the 40-year-old co-founder of Digiticians in Waltham, Mass., which sells preventive-maintenance software for computer users. "That rage is being driven by the increasing complexity of hardware and software." Smith counts some six national companies, 20 regional players, and 240,000 individuals offering PC-rehab services. When he started in 2000, he found only one local competitor and no national ones. Remember all those vinyl-pocket-protector types in high school whom we would have paid to get lost? We are now paying them to come to our offices.

To be fair, folks who bully their computers aren't completely unjustified in doing so—which is more than I can say for those who microwave CD-ROMS, or shoot at or urinate upon their monitors (more on them later). A typical small-business setup, at home or in an office, now includes an infuriating tangle of PCs and printers, a wireless network, and a broadband connection. What isn't included is a beeper-belted polymath who is readily available to put down pop-ups. "Companies call me and they say, 'We had this computer guy who we used to call, but we can't reach him,'" says Andrew Tomb, 33, who services small businesses through his solo operation, Onsite Solutions, in Kansas City, Mo. "I've seen some suspicious-looking mice injuries. I don't ask questions."

Of course "most people don't talk about the damage they do," says Kent Norman. "The best computer rages are caught on security cameras," which—fortunately, for lots of reasons—most small businesses don't have. Norman, who teaches cognitive psychology at the University of Maryland, where he is also lead scientist of the laboratory for automation psychology, recently polled 2,700 computer users about their bad selves. He contends that some 20% of computer users have gotten "extremely frustrated" and have inflicted physical damage. His confessors include a restaurant manager who tossed a laptop into a Frialator (wrecking both machines); someone who threw a monitor through a second-story window (it was closed); and three users who claim they've shot their computers (all at firing ranges). "There's a lot of stuff being broken out there," says Norman, who for fun has blowtorched a computer mouse and whacked a keyboard with an ax. "People lie about it. They say, 'It was an accident' or 'It fell off my lap.'"

Despite his sophistication, Norman harbors no sympathy for the victimized computers. "They are just machines," he intones, cyborg-like. "It really doesn't matter a whole lot what you do to them. We get into trouble when we deal with computers as if they were human beings." Norman, 58, has conveniently forgotten that a whole generation once called its cars by names such as "Ethel." In fact, his iciness suggests another business opportunity to me: cybernetic relationship therapy, wherein I counsel machines and their owners. ("You, you've got to stop slapping the side of the monitor," I'll instruct, pointing to the human. "And you, you've got to stop sending error messages.") I'm going to do my best to copy the style of Dr. Phil—which I should finally be able to study if I can ever get my @#$%&* TiVo working.