A support engineer published expiration dates of builds on the Microsoft Answers website



From gHacks:

Microsoft published several Windows 10 preview builds of its upcoming operating system that give interested users a preview of things to come, Microsoft much needed feedback and companies options to test software and services in the new environment.

These builds are not final and improved builds are published by Microsoft regularly which update older builds to the newest version when downloaded.

Beta software, and the tech previews of Windows 10 are that technically, expire especially when the software is commercial in nature.

  Windows 10 builds stop booting when they expire