Windows Mobile Apps Won't Work on Windows Phone 7

Microsoft has confirmed that applications written to run on its aging Windows Mobile 6.x phone operating system will not run on its brand new mobile OS.

In designing its forthcoming Windows Phone 7 Series mobile device operating system, Microsoft (NASDAQ: MSFT) had to do a "reset" of what it has been doing in the phone handset market in the past, according to a recent post by Microsoft's Charlie Kindel at his Windows Phone Development blog.

"Developers, designers, and producers of applications, games, and content these days are demanding that we be different," Kindel's post said. That's a major reason why the newly introduced system has a brand new user interface (UI) -- it bears a resemblance to Microsoft's Zune HD UI instead of using the older Windows Mobile UI.

As part of the reset, Microsoft not only imposed physical requirements -- such as three dedicated buttons for Home, Back, and Search -- but also additional UI design specifications, including support for multitouch screens.

"Windows Phone 7 Series represents an inflection point for Microsoft, as well as the partners and developers we work with. In fact, these audiences have been most vocal about wanting a new OS. We have dramatically changed our approach to the UI and are taking accountability for the end-to-end user experience," a company spokesperson said in an e-mail to InternetNews.com.

Because of that, Windows Phone 7 Series devices take advantage of newer Microsoft development technologies -- specifically, Microsoft's Silverlight media presentation technology, .NET, and its XNA game programming developer kit and runtime.

"To deliver what developers expect in the developer platform we've had to change how phone apps were written. One result of this is previous Windows mobile applications will not run on Windows Phone 7 Series," Kindel's post added.

That announcement answers some of developers' questions regarding Windows Phone 7 Series in advance of Microsoft's MIX 2010 Web developers conference coming up March 15 through 17 in Las Vegas.

Do Microsoft Windows Mobile 6x Devices Have an Upgrade Path?

Still unanswered is whether Windows Mobile 6.x devices will be upgradeable to run Windows Phone 7 Series, although many observers believe never the twain shall meet.

Microsoft CEO Steve Ballmer debuted the new system last month at the Mobile World Congress (MWC) in Barcelona.

At the time, Ballmer and other Microsoft execs had little specific to say about Windows Mobile 6.x and the devices it runs on, despite the fact that OEMs just began shipping handsets built on 6.5 in October.

That seemed inauspicious to many observers, and rumors have been flying ever since Windows Phone 7 Series' introduction that the 6.x phones are in their death spiral.

Company officials admitted earlier this week that, due to the strict requirements as to what devices can run