Windows Seven Release Candidate (RC) has been released, replace beta version, that is upgrade from 7077 beta to 7100 RC. Microsoft has open Seven RC download for public, which is more stable than previous version.
You can download free original copy from:
It will continue run until 1 March 2010. But for computer freaks like me, I may have reformat several times during this period, so I will just try it out. You can read the detail at the web page given.