The rise of Bill Gates, from Harvard dropout to richest man in the world

With a net worth of more than $87 billion, Bill Gates is still the richest person in the world.

It wasn't dumb luck that got him that spot - Gates is a smart, aggressive business mind who was never afraid to make enemies in his drive to take Microsoft to the top.

From Harvard dropout to an Albuquerque rental office to the top of the world, here's how Bill Gates turned Microsoft into a global force, and became a billionaire in the process.