Microsoft claims 270 million "active users" of Windows 10 so far, likely a count of the number of monthly active users, spread across a wide variety of platforms, including (presumably) Xbox, phones, and IoT devices. That's up about 25 million a month from the last Microsoft-provided data point of 200 million from December. Windows 7 added about 20 to 25 million users a month for most of its lifetime, although the numbers now are calculated differently (Win7 shipped copies versus Win10 monthly actives).
The latest Windows 10 beta test version, build 14295, has been released to the Windows Insider Slow ring. Frequently, release to the Slow ring is accompanied by release of full ISO images of the build -- useful for those creating virtual machines and helpful for those who want to perform a clean install. At this point I don't see the files available for download, but Windows spokesperson Gabe Aul points to the Windows Insider signup page. Bootlegs of 14295 have been available for several days.
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