You can try out a beta version of Windows 10 on your phone now

It’s here: Windows 10 for phones is ready for the public to preview. Microsoft announced that it was pushing the beta OS to intrepid testers through its Windows Insider program on Thursday.

To download the new technical preview, you’ll need to grab it through the Windows Insider app after signing up for the Windows Insider preview program. You’ll also need an eligible Windows Phone. Once you’re signed up, you’ll receive new builds as over-the-air updates. Here’s the full list from Microsoft:

  • Lumia 630
  • Lumia 635
  • Lumia 636
  • Lumia 638
  • Lumia 730
  • Lumia 830

You might notice that this list of devices does not include many of the high-end devices that run Windows Phone, including the 900 series and HTC’s One M8 with Windows Phone.

Update 2:30 ET: Good luck if you’re trying to install the update. Many power users and Microsoft journalists are furiously complaining on Twitter that even devices that are supported may not be able to pull down the update, as well as various other installation issues. If you’re having trouble getting the update to show up, try reinstalling the Windows Insider app. Our own Kevin Tofel has successfully installed the preview on a Lumia 830, but he reports that it’s a slow process.

However, a French language page briefly listed HTC’s Windows Phones as among the devices can grab the preview, so availability might differ by country in the future.

The Technical Preview is a close cousin to the version of Windows 10 for phones that Microsoft previewed at its big consumer-oriented summit last month. Bigger changes expected for Windows 10 on mobile devices include a revamped notification center that syncs with desktops running Windows 10, Skype integration with the its text messaging app and Microsoft’s new Spartan browser, although some of Microsoft’s promised features (like the new browser) might not be available in this build. There should also be a host of subtle interface tweaks that should improve the user experience. Here’s a Microsoft blog post about what to look for in the technical preview.

The Windows 10 technical preview for desktops has been available through Windows Insider since last fall.

Keep in mind that you probably shouldn’t install this on your main phone. It’s a very early beta version and there’s sure to be bugs. So get your spare Lumias out and charged — Microsoft appreciates your willingness to test its pre-release software:

Microsoft post-announcement bump: 170,000 new Windows beta testers

Because no devices running Windows 10 went on sale after Microsoft announced its consumer-facing features on Wednesday, it’s hard to tell if it’s going to be a hit in stores. But Microsoft certainly generated some excitement with its unveiling: engineer Gabriel Aul tweeted Thursday night that more than 170,000 people had signed up for the Windows Insider beta testing program since the event.

Microsoft previously announced that it had seen 1.7 million people sign up for Windows Insider on Wednesday since the program launched last September.

Windows Insider is a important part of Microsoft’s strategy for Windows 10. It provides [company]Microsoft[/company] with feedback on which of its new features are winners and helps squash bugs. It also lets Microsoft engage directly with its most committed users.

As with a smartphone flash sale, it’s logical to assume that people who beta test new versions of Windows will feel more invested in the platform and be more likely to evangelize for it — which is key to CEO Satya Nadella’s stated mission of moving people from “needing Windows to choosing Windows to loving Windows.”

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The version of Windows 10 for desktops revealed on Wednesday — with new Cortana integration, a smartphone-style notifications pane, and the Xbox app  — hasn’t been pushed out to users in the Windows Insider program yet, but Microsoft promises to release the January preview “in the next week.” You can sign up here. If you’d like to try out Windows 10 for phones, you’ll need the Phone Insider app, and Microsoft promises you’ll get your shot in February.