Microsoft reported a rise in quarterly profit, boosted by strong sales of its Windows operating system, and the company raised its full-year profit outlook, sending its shares up four per cent.

The world's largest software maker said net profit in its fiscal second quarter rose to $4.7 billion, or 50 cents per diluted share, from $2.6billion, or 26 cents per diluted share, in the year-ago period. Revenue rose 30 per cent to $16.37 billion.

Analysts, on average, had forecast Microsoft to earn 46 cents per share on revenue of $15.94 billion, according to Reuters estimates.

The second-quarter revenue and profit growth rates are exaggerated by results in the year-ago period when Microsoft deferred more than $1 billion in net income due to delays in releasing Windows Vista and Office 2007, which hit stores early last year.

For the fiscal year ending in June, Microsoft lifted its outlook. It now expects earnings per share to range between $1.85 and $1.88 per share, up from its previous estimate of $1.78 to $1.81.

It also boosted its revenue outlook range to between $59.9 billion and $60.5 billion from a previous range of $58.8 billion to $59.7 billion.

Microsoft's results and raised forecasts come on the heels of disappointing outlooks from technology bellwethers Intel Corp and Apple Inc. which sent shivers through an already jittery stock market.