Microsoft announced late Monday that it has named former AT&T Wireless and E*Trade executive Michael Sievert as corporate vice president for Windows product management.

Sievert is replacing 17-year Microsoft veteran Tom Button, the current vice president in charge of Windows product management, who has been in that role since the summer of 2003. Button has taken a leave of absence due to family medical reasons, according to a corporate statement. Button is expected to return to Microsoft in a different capacity, company officials said. (Most of Button's Microsoft career was spent in the developer division.)

Like Button, Sievert will spearhead marketing, product management and product planning for Windows client, including the Longhorn version that is due out in 2006.

Sievert has considerable marketing expertise. At AT&T Wireless Services, he has been the executive vice president and chief marketing officer since 2002. Before that, he was executive vice president and chief global marketing and sales officer at E*Trade. He also has held various positions with IBM and Procter & Gamble.

As vice president in charge of Windows product management, Sievert — who will report to Senior Windows client vice president Will Poole — will have myriad responsibilities.

In an interview last year with Microsoft Watch, Button described his role this way:

"I oversee product management for Windows and manage marketing strategy. At Microsoft, product management is the discipline that's responsible for defining and championing the value proposition that describes both what Windows is in its current form and what it needs to be in the future, both internally to the development teams and externally to the customers and partners that depend on it."

In a corporate statement released Monday night, Sievert said: "I am delighted to be joining the Windows team at Microsoft, where I can apply what I've learned in the wireless and financial services industries to help Microsoft deliver outstanding products designed to meet the needs of its customers."

The Windows client team has some key product launches ahead.

Microsoft recently said it plans to deliver a new version of its Internet Explorer browser, dubbed IE 7.0, for Windows XP Service Pack 2, Windows XP Professional x64 and Windows Server 2003 Service Pack 1 customers.

An early release of Longhorn is expected to go to alpha testers in late April. A full-fledged beta is expected later this year. And Microsoft is fielding a number of interim "Community Technology Preview" (CTP) builds of some of Longhorn's key components, including the Avalon presentation subsystem and the Indigo communications one, in the coming months.

The Windows client unit also is stepping up its anti-piracy efforts, and continuing its drive to seed Windows in emerging markets, via its Windows XP Starter Edition programs.