The new Windows 10 preview is ready and free for intrepid testers

If you want to try out the slick new Windows 10 bits unveiled earlier this week, you’re in luck: Microsoft just pushed out the January version of its technical preview for desktops, complete with a few of the cool features Microsoft promised.

You can grab it by signing up for Windows Insider, a relatively new program for Windows beta testing, here. Windows Insider is free to sign up for, and when Windows 10 is officially launched, the consumer-friendly update will be free for the first year.

Beware — the technical preview isn’t for rookies. You shouldn’t install it on any machine you need to do work on. As Microsoft’s Windows Insider site puts it: “If, however, you think an ISO is some kind of yoga pose, this program may not be right for you.”

This build includes new Cortana integration into the start bar, as well as Continuum, a feature that improves the experience of switching from tablet mode to desktop mode on hybrid computers like Microsoft Surface. Not everything that will eventually end up in Windows 10 is included in this beta build. It lacks Microsoft’s new Spartan browser, for example. Although the build includes the new Xbox app, it doesn’t yet have the ability for an Xbox One to stream games directly to Windows 10 computers.

This build is only for desktops, and we still don’t know exactly when we’ll see the Windows 10 preview for phones. Microsoft promised it in February, so if you’re waiting on it you might as well sign up for Windows Insider now and download the Phone Insider app.