FIRST LOSS: Microsoft posted a quarterly loss of $492 million, or 6 cents a share, the first negative quarter since it went public in March 1986.

AD STRUGGLES: The loss was caused by a $6.2 billion write-down of its online ad business aQuantive, which it bought in 2007 for $6.3 billion. Its online ad business remains a small and money-losing part of Microsoft.

LOOKING AHEAD: The company's future is tied to Windows 8 and a refresh of its Office and server software suites coming out this fall. Windows 8 is set for sale on Oct. 26.