The company reported net income of $4.47 billion, or 53 cents per share, on revenue of $16 billion, down about 8 percent from the year-earlier period.
Analysts surveyed by Thomson Reuters had expected the Redmond, Wash., company to report net income around $4.69 billion, or 56 cents per share, on revenue of $16.4 billion.
"The slowdown in PC demand ahead of the Windows 8 launch resulted in a decline in operating income," said CFO Peter Klein. Multiyear licensing revenue rose in double digits across Windows, servers and tools, he added.
As well, Microsoft's quarter reflected costs for upgrading customers to the new OS. The company said it deferred $1.36 billion in revenue and 13 cents per share on upgrade promises, which it expects to recover in the current quarter once Windows 8 ships.
The company also said its cash and investments rose to $66.6 billion, up more than $3 billion in the past quarter.
Microsoft shares fell 2 percent to $28.84, down 64 cents, in after-hours trading. They had risen nearly 14 percent in 2012.