NEW YORK ( TheStreet) -- Shares of Microsoft ( MSFT) were down in late trades after the Dow component reported a year-over-year decline in operating income for its fiscal first quarter, citing slow PC demand ahead of its Windows 8 launch. On a non-GAAP basis, the Redmond, Wash.-based software giant reported earnings of 65 cents a share on revenue of $17.36 billion for the three months ended Sept. 30. Non-GAAP results include revenue deferred in relation to the company's Windows Upgrade Offer, Windows 8 Pre-sales, and its Office Offer. On a GAAP basis, excluding this revenue, Microsoft earned $4.47 billion, or 53 cents a share, in the quarter on revenue of $16.01 billion. Operating income fell to $5.31 billion in the quarter from $7.20 billion last year. The average estimate of analysts polled by Thomson Reuters was for a profit of 56 cents a share in the September-ended period on revenue of $16.42 billion. "While enterprise revenue continued to grow and we managed our expenses, the slowdown in PC demand ahead of the Windows 8 launch resulted in a decline in operating income," said Peter Klein, the company's chief financial officer, in a in a statement. "Multi-year licensing revenue grew double-digits across Windows, Server & Tools, and Microsoft Business Division products as businesses commit to our technology roadmap." Microsoft also reaffirmed an outlook for fiscal 2013 expenses of $30.3 billion to $30.9 billion. Windows 8 is expected to be generally available on Oct. 26, and Microsoft CEO Steve Ballmer called the release "the beginning of a new era" at the company in his earnings commentary. ""Investments we've made over a number of years are now coming together to create a future of exceptional devices and services, with tremendous opportunity for our customers, developers, and partners," he added. The stock was last quoted at $28.87, down 2.1%, on after-hours volume of 5.64 million, according to Nasdaq.com. Chipotle Mexican Grill ( MSFT) was under heavy selling pressure after the restaurant operator reported below-consensus third-quarter results and said it sees flat to low single-digit same-store sales in 2013. The Denver-based company posted earnings of $72.3 million, or $2.27 a share, for the September-ended quarter on revenue of $700.5 million, missing Wall Street's average view for a profit of $2.30 a share on revenue of $702.2 million. The stock was last quoted at $256, off 10.5%, on volume of nearly 700,000. Same-store sales rose 4.8% in the quarter, and general and administrative costs came in at 6.9% of revenue, an increase of 60 basis points from the same period a year earlier.