Microsoft announced today that the Windows 8.1 Enterprise Preview is now available. It’s not clear why this release trailed the Windows 8.1 Preview for Windows 8 (Core and Pro) and RT by a month, but it’s here now, and it provides a peek at some changes that will be unique to this business-oriented version of the next Windows update.

A couple of notes before diving in here.

First, I assume this product is really best described as Windows 8 Enterprise with the Windows 8.1 update installed, but this is one of the screwy things about Windows 8.1, which is alternatively described as an update (like a service pack or feature pack) and a new version of Windows. Here’s the real deal: Since Microsoft is not extending the Windows 8 lifecycle policy with this release, it is just an update and not a new Windows version.

Second, it’s worth pointing out that the features in Enterprise build on top of the other business-oriented features that Microsoft is adding to Windows 8 with the Windows 8.1 update. And these features are actually pretty considerable. If you’re not up on this, please check out In Blue: Business Features in Windows 8.1 and Microsoft Makes Its Case for Windows 8.1 in Business for my previous explanations of these changes.

“Today, I’m excited to announce that Windows 8.1 Enterprise Preview is now available for download for customers to start testing the operating system in their environments,” Microsoft’s Erwin Visser writes in a post to the Windows for Your Business blog. “Windows 8.1 Enterprise Preview builds on the Window 8.1 Preview which is currently available, adding premium features designed to address mobility, security, management and virtualization needs of today’s enterprise.”

The following new features are provided in the Windows 8.1 Enterprise Preview:

Windows To Go Creator. This tool can be used by IT to create a fully manageable corporate Windows 8.1 desktop on a bootable external USB drive for Bring Your Own Device (BYOD) scenarios or so that contingent staff can access the corporate environment securely.

Start Screen Control. New Windows 8.1 policies help IT control the layout of the Start screen on company-issued PCs and devices and prevent users from customizing their Start screen to ensure consistency across individual workgroups or the entire company.

Additionally, Windows 8.1 Enterprise will continue to offer a set of “premium features” that are unique to this SKU, including DirectAccess (a VPN replacement), BranchCache (for caching content downloaded over a WAN), Virtual Desktop Infrastructure (VDI) support, AppLocker (for blacklisting files and apps) and Windows Enterprise Side-Loading (for Metro-style apps).

I’ve actually had this thing for a while on a Windows To Go stick and am embarrassed to say I’ve never even booted it up. I’ll try to do so soon. But you can download the Windows 8.1 Enterprise Preview from the TechNet web site now. (The product key is YNB3T-VHW8P-72P6K-BQHCB-DM92V). Like the Windows 8.1 Preview for Windows 8 and RT, it expires in mid-January 2014.