Source -The Windows 7 Professional Test Drive website is designed to deliver a free taste of the latest iteration of the Windows client with as little effort as possible on behalf of the end user. There are other ways in which customers can try out Windows 7 to see what the new operating system has to offer. Users can download the actual bits for Windows 7 Enterprise and install a trial edition of the OS that is time-bombed and set to expire after 90 days. Similarly, customers can download a Virtual Hard Disk image with Windows 7, also time-bombed, but which requires less work, no installation, and comes pre-configured. You will be able to find links for both at the end of this article.
Free Windows 7 RTM Test Drive from Microsoft - Via the Windows 7 Professional Test Drive website - Softpedia