Steve Ballmer, 54, forms a unique and controversial figure as chief executive of the world's largest software company.  His cracking, nasal voice brings to mind Chris Farley and his quirky sense of humor only strengthens the comparison.

But at the end of the day Mr. Ballmer means business, and he's been the undisputed leader since Bill Gates departed in January 2000.  Ballmer has led the company through some of its most glorious successes -- Windows XP, the Xbox, and Windows 7 -- but has also been on the helm for some of its less glorious campaigns -- Windows Vista, Windows Mobile, tablet efforts, and Kin.

A study by Glassdoor.com shows that the company's above outlined struggles and Mr. Ballmer's strong personality may be outweighing his successes.  The survey of 1,000 departing Microsoft employees found that only a razor-thin 51 percent majority approved of Mr. Ballmer's job performance.

That's number seems more troublesome given that overall the employees were very satisfied with Microsoft -- rating it at 3.5 out of 5, just below the 3.8 out of 5 that Apple and Google both received in similar recent studies.

This year has been a stormy one for Microsoft.  Despite the wild sales success of Windows 7, the company's stock has dropped 20 percent and the company was forced to pull its new Kin phones off the market only weeks after it released them.  The latter failure cost Mr. Ballmer a bit of his yearly bonus.  Mr. Ballmer also drew fire for killing Microsoft's Courier dual-screen tablet concept, which had drawn much excitement.

Some observers say that Microsoft's performance with its new smartphone operating system, Windows Phone 7, and its upcoming tablets may determine Mr. Ballmer's ultimate fate and whether he is suitable to keep leading Microsoft.  A failure in these arenas would be a massive loss for Microsoft, and potentially catastrophic to Mr. Ballmer's career.

Rebecca Wettemann, analyst at Nucleus Research comments, "This is a pretty critical moment for Microsoft, particularly as we see a shift to people wanting access to the information they need from any device.  The winner in this space will be the one that puts a toy in the consumer's hands that is also a good business tool for a worker's hands."

She adds, "[Oracle CEO] Larry [Ellison] has Fusion and [Apple CEO Steve] Jobs has the iPad, but Microsoft has had things in development for a while without being able to get those things to market.  That's the kind of thing that sparks a leadership change."

If Mr. Ballmer has his way he would retire on his own volition at around 2018, according to his past statements.