The trial is a fully functional copy of Windows 7 Enterprise, the SKU equivalent of the Enterprise edition, which users can try for 90 days.
The ISO that the software giant provides is time-bombed, and will expire after 90 days since the first installation, at which point customers need to either buy a license or uninstall the operating system. The Slmgr reactivation method doesn’t work on the Enterprise edition.
At the time of this article, one mention on the trial’s download page revealed that “The 90-day Trial is offered for a limited time and in limited quantity. The download will be available through December 31, 2011, while supplies last.”
Supplies have lasted since Windows 7 became commercially available, and I don’t think that they’ll dry up anytime soon.
In addition, the date presented by the software giant in this message has been modified a number of times, and my best bet is the fact that Microsoft will work its magic and push back this deadline even further into 2012.
I don’t believe that the company plans to discontinue the availability of Windows 7 Enterprise 90-day trial downloads at the end of 2011, as the page currently states.
Of course, the free Windows 7 ride will end at some time, but most likely, this will be sometime after Windows 8 is released to consumers worldwide next year. In the meantime, Microsoft still wants customers to upgrade to Windows 7 and not wait for Windows 8, so it might be a good idea to keep the free trial alive.