Microsoft Corp. said its fiscal first-quarter profit fell on Thursday, hurt by a dip in computer sales running its Windows operating system and the deferral of some revenue ahead of upcoming releases of its core Windows and Office products.

The world's largest software company said quarterly profit fell to $4.47 billion, or 53 cents per share, from $5.74 billion, or 68 cents per share, in the year-ago quarter.

Sales fell 8 percent to $16.01 billion, partly caused by the dip in demand for PCs running Windows, as consumers held off new purchases in the tight economy or opted to buy tablet devices instead. The decline was exaggerated by Microsoft's deferral of some revenue which it will regain next quarter.

Microsoft is hoping to revive PC sales next week with the launch its new Windows 8 system on Friday.