The possibilities where you can do the download of RC2 or RTM :
1.) If you were to have a Connect Id with microsoft ( Which needs an
invitation from some one you know who has it )
2.) If you have filed a bug with the earlier beta versions of Vista, you
would have got a mail with the link to do the download of RTM Version of
Vista ( Which is ruled out as the time has lapsed to file bug reports to
vista )
3.) If you are a subscriber of TechNet or MSDN, you will have the access to
download the RTM Version of Vista.
All the best,
Jai
Sr.Tech Support Exec.
Windows Vista