Microsoft's Chief Executive Officer Steve Ballmer, while meeting with a group of Wall Street analysts and shareholders in New York on Thursday, commented that the market performances forecasted for Windows Vista were "overly aggressive" and asked analyst to temper their predictions.

Ballmer's words measured a 2.7 magnitude on the Microsoft stock "Richter" scale; a 2.7 magnitude Microsoft stock-quake, because the Redmond Company's shares dropped as much as 2.7% on the day following Ballmer's speech. Driven by Ballmer's assessment that Windows Vista will fail to meet the overly optimistic analyst estimates for the 2008 fiscal year, the company's shares have experienced the worst depreciation in the last nine months.

"Some of the Windows revenue forecasts I've seen are overly aggressive," were the words of the Microsoft's CEO that catalyzed the share drop. "You shouldn't think of a huge surge in fiscal year '08 relative to '07. There's a few that think we are going to do so much better than PC growth."

The fluctuation in Microsoft's shares value was 72 cents, dropping to $28.74. Analysts have pointed out that Ballmer's Windows Vista reality check is the source of the share's fall. In the aftermath of Ballmer's speech and of Microsoft share drop, market analysts have overhauled their Vista predictions.

While initially the Microsoft growth rate in the context of the commercial availability of Vista was as high as 15% for the 2008 fiscal year, the forecasts are now focusing on a growth from 8% to no more than 13%.