Developments with Microsoft's new Windows 8 system

The launch of Windows 8 is heralded as the biggest change to the industry's dominant operating system in at least 17 years. It attempts to bridge the gap between personal computers and fast-growing tablets with its touch-enabled interface. Here's a look at events surrounding Microsoft Corp.'s new system:

— Oct. 25: Microsoft holds a launch event in New York for Windows 8, a major overhaul of its ubiquitous computer operating system. Not much new is revealed, as many of the details had been announced before, and the software had been available for testing.

— Oct. 26: First day of sales for desktops, laptops and tablets with Windows 8. Upgrades from older versions of Windows become available.

— Oct. 29: Microsoft launches phone version of new operating system, Windows Phone 8. Windows 8 phones begin shipping that week.

— Oct. 30: SurfCast Inc., a small technology company based in Portland, Maine, files a patent infringement lawsuit against Microsoft over an element in Windows 8 — rectangular icons, or tiles, linked to websites, apps and other items. SurfCast says it developed that in the 1990s. Microsoft says it's confident it can prove the claims are without merit.

— Nov. 12: In a management shake-up, Microsoft says Steven Sinofsky, the president of its Windows and Windows Live operations, is leaving the company. The company does not give a reason. Company veteran Julie Larson-Green is promoted to lead all Windows software and hardware engineering. Tami Reller takes over responsibility for the Windows business while retaining duties as chief financial officer and chief marketing officer.

— Nov. 13: Microsoft releases its redesigned browser, Internet Explorer 10, for computers running the older Windows 7 system. Although Microsoft designed Internet Explorer 10 with Windows 8's touch interface in mind, the Redmond, Wash., company is hoping people will see the browser's potential on their Windows 7 machines.

— Wednesday: Microsoft says about 40 million licenses to Windows 8 were sold in its first month on the market, though that number includes licenses bought by PC manufacturers for machines built but not yet sold. Microsoft didn't provide further details beyond saying that Windows 8 is being embraced by a list of companies that include Johnson & Johnson, British Telecom and Bank of America Corp.

— Thursday: NPD Group says sales of personal computers in the U.S. didn't get any boost from the launch of Windows 8. There's no sign that Windows 8 made things worse for PC makers. Rather, NPD says the weak sales are a continuation of a trend seen throughout this year.