Recently Microsoft released the Release Candidate (RC) of Windows 7. It is solely for testing purpose and should be downloaded and installed only by experienced computer users. It is not recommended to install Windows 7 on your primary home or business computer as your system may crash and you could lose all your important files.

Windows 7 Release Candidate (RC) is the pre-release version of Windows 7. The RC will expire June 1, 2010, and the bi-hourly shutdowns will begin on March 1, 2010. If you are running Windows XP, you'll need to back up your data and then do a clean installation of the Windows 7 RC. After installing, you will need to reinstall applications and restore your files. If you're running Windows Vista, you can install Window 7 RC without having to back up and reinstall your programs and data.


Link: Download Windows 7 Release Candidate


Related: A Complete Guide To Windows 7 Release Candidate