Windows 7 Beta build (7000) is leaked to torrent sites a few days back. Microsoft is expected to release the beta in January 7. But if you don’t want to wait and want to try Windows 7 right away you can download the ISO from torrent sites.
These valid until 30 day evaluation period and needs to be activated to use it continuously. So some one cracked the build and deactivated the activation process, the build won’t ask you for the activation and you can use it as long as you want. Also the crack removes the expiry date of the build.
Don’t ask links here, go to your favorite torrent site and search you will get it.