Ballmer said the changes are in response to desktop users who wanted something a little more familiar on their computers.
The new system, he said, refines Windows 8 by bringing back some options Microsoft eliminated in the fall, such as the start button and the ability to boot a computer straight to the desktop.
The start menu hasn’t returned in the same form, but users can access some options from the start button, such as access to the Control Panel and Task Manager, as well as the ability to shut down or restart the computer.
Microsoft also showed off new additions such as a Pandora-like makeover for Xbox Music, deeper search integration from Bing, and more ways to personalize the look of the operating system.
For example, users will be able to pick from more sizes of Windows 8 tiles, which will also be easier to organize. Also, Windows users will have the option to snap more Metro apps to their screens at once — up to four on one screen.
Microsoft is also adding prominent Windows 8 app partners. Facebook and Flipboard will be making native Windows 8 apps, the company said. Microsoft has also made improvements to some of its own apps, including the camera, which now has more photo-editing tools such as options to enhance color, remove red-eye, change the contrast and brightness balances, and overlay filters.
Ballmer said the company expects to pass the 100,000 application mark in the Windows store by the end of the month, putting it in a slightly better position to compete with Apple and Google on that front.
“The future of Windows is very, very bright,” Ballmer said in his closing remarks.
The update will be free for Windows 8 users, and will be available “later this year” through the Windows store, according to Microsoft. And the company said users should be able to download a copy of the preview starting Wednesday
The developers conference continues through Friday.