Windows 10 is Microsoft"s most secure OS to date and offers improved security and device management options for large corporations.. In order to entice more corporate customers, Microsoft is now offering up a 90-day trial for Windows 10:
...a 90-day evaluation of Windows 10 Enterprise is available through the TechNet Evaluation Center. The evaluation is available in Chinese (Simplified), Chinese (Traditional), French, German, Italian, Japanese, Korean, Portuguese (Brazil), and Spanish (Spain, International Sort). We highly recommend that organizations make use of the Windows 10 Enterprise 90-day Evaluation to try out deployment and management scenarios, test compatibility with hardware and applications, and to get hands on experience with Windows 10 Enterprise features.
Those running Windows 10 Enterprise as an Insider should also be aware that the preview will end on October 1, with notifications of the impending closure starting in September. After that, customers must either register for the 90-day evaluation or purchase the full product to continue using it.
Microsoft has already made the Windows 10 upgrade available to users with Home and Pro licenses, while the Enterprise is will follow on August 1.
Source: Microsoft