A few questions:
1. For how long does the system stand unresponsive. One of my computers was in that state and at that point in the install for about 10 minutes before it decided to actually do something. Once it started up again, all was good.
2. When you say "excluded all the bad h/w" - how do you know it's bad?
3. Have you attempted an install after removing all but the very basic required h/w (keyboard, mouse, one video card, one HDD, one stick memory)?
4. Have you gone into the BIOS and set it to the "Default" state - this is usually a lowest performance, least problem state. Sometimes an O/S install has problems when the MBO BIOS has been optimized for performance.