Now it's Microsoft's turn to rally developers

When Microsoft Chief Executive Steve Ballmer took the stage at the company's Build conference for developers last October, the software giant was buzzing from the Windows 8 launch the prior week.

The big news for the first day of that Build: Microsoft had sold 4 million copies of the new operating system in just four days.

This year's Build, which starts Wednesday in San Francisco, will be a bit of a reset for Windows 8. The Windows 8 buzz has long since dissipated, replaced by concerns that the operating system isn't sparking PC sales the way analysts, PC makers, and developers had hoped. Since its debut, PC sales have slumped, with some analysts blaming that drop on tepid interest in Windows 8.

Of course, Microsoft is unlikely to acknowledge any slip in momentum. Build, after all, is a a rally-the-troops moment for a crowd that's dependent on Microsoft getting Windows 8 right. And despite concerns about the operating system, Windows 8 has sold 100 million copies as of last month, a huge number in a mature market.

But the company is making a series of changes in the new operating system, and it will explain them to the assembled developers during the conference. Many of the changes are the type delivered to every previous version of Windows, updates to make the operating system work better, fixes to clear some clutter, and tweaks to reduce complexity.

But Microsoft has also taken steps to address vocal criticism of loyal customers who had grown accustomed to the earlier versions of the operating system and were put off by the new, touch-focused, tile-based interface. Some customers wanted easy access to the start menu in the tile-based interface. Another group of customers wanted the ability to launch their PCs directly to the familiar desktop interface.

Last month, Microsoft acquiesced, at least in part, giving users some of what they were after. When the preview edition of Windows 8.1 debuts at Build, it will include something that Microsoft is calling a "Start tip," something of a half-step toward the old Start Button that launched the Start Menu. Clicking on the tip, a Windows logo in the lower left corner of the screen, will take users to their Start screen. And Microsoft is also letting users chose which mode -- desktop or tile -- they want to their PCs to boot to.

Microsoft executives will likely spend much of the conference pumping up developers with the raft of updates. Those changes will likely fall into three buckets--fixes that make the operating system easier to use, changes based on the telemetry data that Microsoft collects from users as well as verbal and email feedback, and new innovation.

The company will run through demos, highlighting new scenarios for Windows 8 users for which developers can build applications. Microsoft, for example, is making it easier to run multiple windows in a variety of sizes in the tile-based interface. On a 10-inch tablet, held in landscape position, users can have as a many as four open windows at the same time, making it easier to compose an email while culling information from a Web site and a spreadsheet.

The company is likely to highlight momentum as well. Microsoft has been playing catch-up with Apple in its online app store for its PC operating system. The company is changing the design of the app store, offering suggestions for customers based on previous purchases. The company tweaking the store layout to give more details and provide larger images for apps. It may update the number of apps in the online store.

And the company is likely to show how its family of products work together. Windows Phone and Xbox work ever more smoothly with Windows 8. And SkyDrive, Microsoft's online storage service, will be baked even more deeply into the operating system, letting users save files directly to the Web with little effort.

At last fall's Build, Ballmer told developers that "Windows 8 is the best opportunity for software development today." With PC sales slumping, Microsoft will work to convince developers that that optimism is still valid.