Microsoft officials say there are about 450,000, or 30 percent of its total registered Windows 10 Insiders, actively testing the next Windows release .



From All About Microsoft:

ack in mid-October, shortly after Microsoft released the first public Windows 10 Technical Preview build, Microsoft said 1 million people had signed up as Insiders to test Windows 10.

When they released its second preview update to the Windows 10 Technical Preview in November, Microsoft execs said the next officially sanctioned Windows 10 preview update would be in early 2015. There have been a couple of unsanctioned leaked builds since then, the latest of which (Build 9901) shows off some of the UI changes Microsoft is expected to make part of its upcoming consumer-focused preview in January.

  Microsoft: We have more than 1.5 million Windows 10 Insiders