The release date for Windows 8.1 is nearly a year after the debut of Windows 8, a dramatic overhaul of the operating system that has been powering most personal computers for decades.
Microsoft Corp. unveiled its plans for Windows 8.1 three months ago, but hadn't set a release date until Wednesday. At test version of Windows 8.1 that may still include some bugs has been available since late June.
Windows 8 represented Microsoft's attempt to create an operating system that works well on tablet computers, as well as on laptop and desktop machines.
But the overhaul confused and frustrated many people, resulting in disappointing sales of devices running on Windows 8. One research firm, International Data Corp., has even blamed Windows 8 for deepening the slump in PC sales as more people rely on smartphones and tablets to connect to the Internet.
Microsoft, which is based in Redmond, Wash., also absorbed a $900 million charge to its most recent quarterly earnings to account for its expected losses from a company-produced tablet, called Surface, which relies on a slimmed-down version of Windows 8.
Windows 8.1 is Microsoft's attempt to make the operating system easier and more appealing to use. It will be available as a free update to owners of Windows 8 machines.
The first laptops and PCs featuring Windows 8.1 already installed are scheduled to go on sale Oct. 18.