W7 will not install.

I have hit a brick wall trying to install this program.  Booting from the DVD, I cannot see all my drives. The partition to which I want to install is not shown.  When I use setup.exe once I have booted from Vista, all partions show and all seems well until the end when it tells me the install was unsuccessful and then it removes all the changes.  I am doing this with my anti-virus program inactivated.