Se você está falando sobre o teste de 90 dias do Windows 7 Enterprise, precisará reinstalar após o período de avaliação. De Microsoft TechNet :
The 90-day Trial is the full working version of the Windows 7 Enterprise, the version most of you will be working with in your corporate environment. It will not require a product key (it is embedded with the download).
The 90-day Trial will shut down once every hour when you have reached the end of the 90-day evaluation period.
The 90-day Trial is offered for a limited time and in limited quantity. The download will be available through March 31, 2010, while supplies last.
- After the 90-day Trial expires, if you wish to continue to use Windows 7 Enterprise, please note that you will be required to purchase and perform a clean installation of Windows 7, including drivers and applications. Please keep this in mind; Windows 7 Enterprise is not available through retail channels.