Microsoft is still trying to working with device makers to come up with the proper mix of machines at different prices to appeal to consumers and corporate customers, said Peter Klein, the company's chief financial officer.
"This is a big, ambitious reimagining of Windows and this quarter was the first step in that process," Klein told analysts in a Thursday conference call.
Besides debuting Windows and Surface during the most recent quarter, Microsoft also released a new version of its operating system for smartphones.
If Microsoft's revamped software for tablets and smartphones catches on, it would help the company overcome a downturn in PC sales, which has reduced licensing revenue during the past year. Worldwide PC shipments fell 3.5 percent last year, marking the industry's first annual decline since 2001, according to the research firm Gartner Inc.
Despite Microsoft's high hopes and an elaborate marketing campaign, Windows 8 appears to have gotten off to a tepid start. Technology reviews have panned the software as too confusing and cumbersome to navigate, and none of the hundreds of devices running on Windows 8 emerged as a breakout hit during the holiday season.
A big chunk of Microsoft's Windows revenue in the holiday-season quarter came from sales that were made before the new operating system's release. Excluding revenue that had been deferred from previous quarter, Windows revenue increased 11 percent from the same period in 2011.
Reiterating information released earlier this month, Microsoft said it has licensed more than 60 million copies of Windows 8. That puts the redesigned system on the same early sales trajectory as its predecessor, Windows 7, after it came out in 2009. It's unclear how many of the devices that have licensed Windows 8 are still sitting on store shelves.
AP Technology Writer Barbara Ortutay in New York contributed to this story.