Goldman Sachs technology analyst Sarah Friar sees challenging times ahead for Microsoft in 2011 as it attempts to address the threat from tablet computers such as the iPad and mobile operating systems such as Android. In a research note released this weekend, Friar wrote that it will be a "more challenging year" for Microsoft with top-line growth slowing from 12 percent to seven percent.

"A tablet response is still not forth-coming and our early read on Windows Phone 7 has not yet changed our view that Microsoft's share in mobile OSes will remain at only the single-digit level," Friar wrote. "For an unlocking of shareholder value, we continue to look for a more aggressive dividend, a more focused consumer strategy, and stronger Cloud-Azure traction."

That's hardly a vote of confidence for Microsoft, which in 2010 lost its title as the most valuable technology company in the world. Goldman Sachs lowered its rating on Microsoft in October from "buy" to "neutral" and cut back its stock price outlook.

"We believe the intrinsic value of shares cannot be unlocked if the status quo remains, and we have increased caution near term on a more elongated PC refresh cycle, combined with the newer threat of notebook cannibalization from tablets, where Windows does not yet have a presence," Friar wrote in a report at the time.

It doesn't appear as if Friar's opinion has changed. Goldman now has a 12-month price target on the company of $29 per share. (The stock is trading this morning at $27.24).

Related: "Report: Microsoft to show off new set of tablet PCs at CES."