Microsoft, it’s time. For the past year the company’s promised that Windows 10 would finally turn the tide in the company’s favor. The chance to prove that starts Wednesday, as Microsoft’s Build developer’s conference opens in San Francisco.

We already know that Windows 10, which has been slowly revealed to us through a very public development process, aims to be a unified OS that will work the same on desktops, notebooks, tablets, phones, and more. On top of it will run a new breed of universal apps, software that can run on all platforms with minimal reconfiguration. It’s the direction Microsoft has to take if it has any hope of regaining ground from iOS, Android, and other competitors.

Windows 10 is just the centerpiece of Microsoft’s larger effort to win back users and developers alike, however. Here are the other big announcements we expect at the conference—that is, if Microsoft expects to stay on course.

1. A focus on Windows 10 phone

Image: Mark Hachman

We expect Microsoft to talk much more about Windows 10 for phones. On the whole, the company’s vision for Windows on mobile devices appears far less mature than its plans for larger screens. The most recent build is just starting to flesh out the Continuum vision of altering Windows’ appearance to favor a touch-centric tablet mode. Also, regardless of whether Microsoft officially agrees with the views of a former designer who explained away the flaws of Windows 10 for phones, there are a number of design inconsistencies that bear resolution.

Stephen Kleynhans, an analyst for Gartner, thinks that might include some new hardware announcements. Flagship phones, anyone?

2. Universal apps or bust

Windows 10 may frame the conversation, but I’d be amazed if universal apps weren’t the primary thrust of Build.

“For a couple of decades Microsoft ‘won’ the market because it won the hearts and minds of the developer community,” Kleynhans said. Not anymore: “The new crop of developers and startups are looking elsewhere (iOS and Android) before they look at any kind of Windows development.”

Windows 10’s Mail app will essentially be the same as the app for Windows phones.

Microsoft has led the way in developing “universal” versions of apps like Calendar, Mail, Maps and Photos, as well as teasing the universal versions of the Office apps that are virtually guaranteed to be released this week. Microsoft will undoubtedly encourage developers to follow suit with their own apps—hopefully with a beefed-up version of the universal app development tool it released last year. The thinking, of course, is that developers can write apps for the millions and millions of desktop PC users—and pick up some incremental Windows phone users in the process. The multi-billion-dollar question will be whether those developers will buy into that way of thinking.

3. Making the app store universal

We’ve known about Microsoft’s vision for a universal app store for about two years, tying together mobile and desktop platforms. But it didn’t materialize in Windows 8.1.

“We should have one set of developer APIs on all of our devices,” Terry Myerson, who oversees Microsoft’s operating system group, has said. “And all of the apps we bring to end users should be available on all of our devices.”

Mark Hachman Microsoft’s app store simply needs to improve.

Actually putting them in user’s hands, however, will require a universal store that sells those universal apps with licensing terms and user reach that developers will find attractive. (Note that I’m not expecting a “universal” apps store to include the Xbox One platform, yet. I would expect that that’s on the roadmap.) Let’s hope Microsoft does some spring cleaning and purges its “crap apps” in the process. “They need to shore up support for Windows 10 Universal App development,” added Michael Silver of Gartner,

4. Office as a platform: Office 365 APIs

Microsoft may also outline plans for third-party app development for Office. CEO Satya Nadella himself tipped this hand during last week’s earnings call: “At Build next week I will talk even more about Office as a platform,” he said, “and how developers can connect into the Office framework to both harness the rich data and have their own app extensions available to ultimately a billion-plus Office users.”

Mark Hachman It’s likely a significant portion of the Office user base doesn’t even know that the Office App Store exists.

Given all of the sessions about ”Office 365 APIs” on the Build schedule, it’s a safe bet that this is the phrase that will be used on stage. Office 365 APIs should allow third-party apps to hook into Office, most likely for authentication, additional functionality, and to tap into Microsoft’s business intelligence.

It’s also possible that Microsoft will reboot its 2013 Office App Store, which tried to jump-start developers by creating add-ons for Word, Excel, and others. But users either failed to understand that the plugins were there or refused to use them. Developers, meanwhile, stopped contributing code. The bottom line: the Office App Store is barren.

5. Windows as a service

Last week, Nadella said that he believes Microsoft should have an “annuity” or “subscription” relationship with both consumers and business customers, asking them to pay for services like Office 365 or Xbox Live on an annual or monthly basis. Windows 10, he said, “will be a service across an array of devices and will usher in a new era of more personal computing. An era where the mobility of the experience, not the device, is paramount.”

Will we eventually subscribe to new builds of Windows?

Microsoft has already trademarked the name “Windows 365”—more evidence that a subscription service is nigh.

Nadella's remarks occurred too recently to be ignored at Build. Gartner’s Kleynhans, however, thinks substantive information could wait until Microsoft hosts its financial analyst meeting later this week, or perhaps even the Microsoft Ignite cloud infrastructure show on May 4, when Windows pricing is also expected to be announced.

While those will likely be the biggest events at Build, Microsoft still has plenty to do to keep moving in the right direction. What do you think needs to happen? Let us know in the comments.