Windows 8.1 will be available to PC makers in late August, paving the way for a holiday launch for computers running the updated operating system, Microsoft told AllThingsD on Monday. The news comes on the first day of the company's yearly partner conference, taking place in Houston this week.

A preview of the updated software was released for download in late June, and fixes a number of critical complaints users had with Windows 8. The drastic redesign announced in 2011 and released in 2012 introduced us to Microsoft's "Modern" design and earned a fair amount of criticism for offering a more mobile, app-based experience on desktop computers.

Windows 8.1 attempts to find a middle-ground in many ways. The biggest may be that Microsoft has brought back the start button (though with a different purpose) and made it easier to access the classic Windows home screen for users that still don't like the new tiled UI.

Windows 8's "Modern" design is also getting a few new improvements, including more tile size variety, and enhanced multi-tasking with up to four apps fitting onscreen at once. The update also features 3D printing support through a partnership with Makerbot, universal search and a new API.