BOOK REVIEW / Follow the nerd instinct and make a billion: Hard Drive: James Wallace & Jim Erickson - John Wiley & Sons pounds 14.95

BILL GATES is an ugly sort of chap. At 36 going on 19, spots, dandruff and checked sports shirts are still high on the agenda, while personal hygiene and grooming come somewhat lower. If your daughter brought him home, you'd probably take her aside and ask her what she was doing with such a nerd.

At that point she would explain that he was the richest man in America, having become the youngest billionaire at 31; that he was now worth about dollars 6.8bn ( pounds 3.4bn); that he had started revolutionising the computer industry while barely out of short trousers; and that in doing so, his software company, Microsoft, had run rings around IBM.

Whether that would change your view on Bill Gates as a potential son-in-law is immaterial. You would at least have to admit that under your roof stood one of the business phenomena of the 20th century. But boy, what a weirdo. Appearances aside, Gates has picked up some strange habits on the stairway from a wealthy professional background in Seattle to billionaire heaven. Reciting the Sermon on the Mount by rote was an early one; rocking back and forth like a Hasidic rabbi and memorising the car number plates of his executives came later.

Gates's Microsoft empire did not so much rewrite the ground rules for the personal computer industry as invent them. The two existing orthodox business structures were complete non-starters: US conventional management - business by committee - crippled any initiative that existed at IBM and the rest of the computer establishment; Japanese robotic dirigisme, which had destroyed the Western manufacturing base, was simply unable to harness the anarchic brains of the pizza-guzzling, anorak-wearing, science- fiction addict constituency of computer programmers. Gatesism - 15-hour days, sleeping under the computer and screaming abuse at the troops - may not make the handbooks of the management gurus, but it got Microsoft where it is today.

At the same time, Gates can lay claim to some of the moral high ground. It is not he who draws a dollars 1m-plus salary and swans around in corporate jets and chauffeured limos, it is the heads of America's bankrupt manufacturers whose trusting shareholders and redundant workers are paying the price. His paper wealth derives from Microsoft's stratospheric share price; his salary hovers around dollars 300,000 a year, less than one-tenth of America's best paid chief executives.

Gates plays hardball both within and outside Microsoft. Inevitably, the list of enemies has grown exponentially. IBM, too stupid to see the writing on the computer screen when it invited Microsoft in to make its new personal computer work, was dumped on in every way. It is now involved in an unlikely marriage with Apple Computers to try to get Gates.

Apple itself claimed that Microsoft stole its ideas and banged in a dollars 4bn lawsuit, which the courts have so far rejected. Smaller software outfits claim that Microsoft indulges in 'date rape' - courting them to talk about joint ventures and then stealing their ideas. The US anti-monopoly authorities want to know if Microsoft does too much.

In all likelihood, none of these foxes is likely to catch the Microsoft rabbit. Its operating systems are now so established as the standard for the personal computer that, short of riot, revolution and nuclear holocaust, they cannot be undone. Bill Gates's rivals can't understand him and even if they could, they don't have the energy to cope with him. They just want him to get married and take a bit of holiday, like the rest of them, so they can catch up a little.

Hard Drive, written by two Seattle journalists, does as well as anyone can to explain Bill Gates. Technical jargon, thankfully, is kept to a minimum, as is the penchant of so many American business biographies for irrelevant and unverifiable detail. Instead, the book outlines with some humour how Gates got to the top - a combination of computer brilliance, obsessiveness and self-belief - without going too heavy on the analysis or the lessons his story holds for others. But then that would probably be an impossible task. To know Bill Gates is to be him.