SEATTLE, Jan 26 (Reuters) - Microsoft Corp said on Monday fiscal second-quarter profit fell, as sluggish personal computer sales dampened demand for Windows software and the company had a one-time tax expense relating to an audit in the United States.

The world's largest software company reported profit of $5.86 billion, or 71 cents per share, compared with $6.56 billion, or 78 cents per share, in the year-ago quarter.

Sales rose 8 percent to $26.5 billion, largely due to the acquisition of Nokia's phone handset business.

(Reporting by Bill Rigby; Editing by Meredith Mazzilli)