Influential hedge fund manager David Einhorn wants Microsoft CEO Steve Ballmer to step down and he has good reasons for that call.

Einhorn, the manager of the Greenlight Capital fund and a long-time Microsoft shareholder, told the audience gathered at the annual Ira Sohn Investment Research Conference in New York on Wednesday that Ballmer's continued presence is the biggest overhand on Microsoft's stock.

Ballmer's problem is that he's stuck in the past, Einhorn said. He's allowed competitors to beat Microsoft in huge areas, including search, mobile-communications software, tablet computing and social networking.

Ballmer, Einhorn said, weighed down the stock and he must give someone else a chance. His fund owns about 9 million Microsoft shares (or about 0.11 percent) and has $7.8 billion of assets.

Why does Einhorn want Ballmer to quit? He has good reasons.

Despite reaping huge profits from sales of its Office and Windows software that run on hundreds of millions of computers around the world, Microsoft's stock has remained stubbornly static, hovering around $25 to $30 a share for much of the last decade. The company's online business, that includes the MSN Web portal and the Bing search engine, is also struggling against the likes of Google and has lost $726 million in the last quarter and $7 billion over the last four years.

Ballmer, who was been at Microsoft since 1980, replaced Bill Gates as the CEO since 2000. However, under him, Microsoft has little truimphs to boast of and more tragedies to show.

Click on the slideshow to find out the top five blunders committed by Microsoft under CEO Steve Ballmer: