The 15 Most Important Changes Coming To Windows 8 Starting Today

Business Insider/Julie Bort

Microsoft shows off a new crop of PCs running Windows 8.1

Microsoft has been talking about its next version of Windows 8 for months, and has already shown off bits and pieces of it.

The new version, Windows 8.1, debuts today. It's not the final version, although anyone with a Windows 8 device can download it from Windows Update or the Windows app store to try it out.

The release comes on the opening day of Microsoft's big developers conference in San Francisco called Build.

We got to take the preview version of Windows 8.1 for a spin. Here's what you can expect to change when you make the free upgrade later this year.