As expected, Microsoft's Windows 8.1 upgrade this summer will be referred to as Windows Blue. Speaking on a conference call today, the company's CFO Tami Reller confirmed the moniker, and revealed that the upcoming software will come as a free update to existing Windows 8 users. Not every single improvement to the OS is known at this point, but Microsoft is expected to detail Windows 8.1's features at its Build conference this June; developers will also get access to a Public Preview.

Many rumors have suggested Microsoft is looking to refine Windows 8 following customer feedback. Nothing has been 100 percent confirmed, but the Redmond company may bring back the Start button, and even introduce an option to boot straight into the Windows 8 desktop, rather than forcing people into the Metro UI. As Windows Blue gets closer, we'll be sure to keep an eye out for any other information regarding changes to the OS.