Microsoft CEO Ballmer to retire Microsoft CEO Steve Ballmer walking off the stage during the launch of the Windows 8 operating system last fall in New York City. (EPA/JUSTIN LANE)

Taking over a major company isn’t easy in the best of times, but whoever steps in to fill the shoes of Microsoft chief executive Steve Ballmer will face a bigger challenge than he or she would have faced even three months ago.

Ballmer’s decision to retire from Microsoft comes a month after he announced a major company reorganization that consolidated a lot of power at the top. Microsoft, then, is searching for a particularly strong new leader just as it's facing what may be the most difficult transition in its history.

Driving the new Microsoft will be a challenge. For years, Microsoft was essentially a company composed of various smaller empires that just happened to make products that worked on the same system. That structure led to many internal clashes at Microsoft that ended up affecting the company’s products. For example, that internal competition has often been cited as a reason why the Windows Phone originally didn’t integrate with Windows PCs, or why some companies have had trouble getting consumer Microsoft products to work with their business services.

The new organization chart was meant to eliminate the tensions and to encourage employees to collaborate as it navigates a rapidly changing technology industry that requires all aspects of the company — hardware, services and software — to be ready to move together with, or ahead of, the market.

It’s a system that’s worked for Apple. But much of that success is attributable to a charismatic, focused chief executive with a clear vision for the company: the late Steve Jobs. Other attempts to emulate Apple's model have been slow-going — just ask Sony, which is working to become “One Sony” after years of operating as a host of smaller units.

To keep its head up in the tech industry, Microsoft needs someone like Jobs at the helm, someone who's not only a smart businessperson but also a leader who inspires loyalty and devotion. It’s clear that the company knows it — Ballmer said as much himself in his statements explaining why he’s stepping down now instead of later. Working through that transition will require stability within the company, and Ballmer acknowledges that’s not a good time to be swapping out people at the top.

“We need a CEO who will be here longer-term for this new direction,” Ballmer said.

So, prospective candidates, no pressure.