Microsoft disables all Win10 Preview keys, but does not affect activated devices.

Computer Store News: Microsoft has disabled all Windows 10 internal participant pre-release keys. This means that if you don't have the internal participant preview program installed on your PC, you can't install the Windows 10 internal participants to preview and activate with the pre-release key, even the newly launched Build 10240 can't be activated.

If you are still running an internal participant preview, your key will remain active. If you need to reinstall Windows 10 internal preview, it's best to wait until RTM is available. A spokesperson for Microsoft said:

All Windows 10 Insider Preview Build pre-release product keys released earlier have been deactivated and no preview Build, including Build 10240, is activated. It does not affect any previously activated devices.

We hope that internal participants will continue to test Build 10240, and we do not support the pure installation of Windows 10240. Windows 10 is designed to be installed on genuine Windows devices, whether it is a Windows internal participant program or a device that participates in a free upgrade offer.

We are about to launch Windows 10 and hope to receive the final feedback!

It is recommended that the Insider members who have activated the system should not try the new installation system.