Assuming you ran the Vista compatibility check and your hardware passed, it might help to try one more installation method. The installation DVD you bought has all Vista versions on it, not just the particular upgrade version you paid for. So, try performing a full install from that DVD of any version of Vista to a freshly formatted hard drive. Don't try to authenticate it, because your authentication code won't work. But as soon as it's installed, put the DVD back in and UPGRADE this Vista installation to the version of Vista that you purchased. Yes, Vista will upgrade Vista! When the upgrade is complete and you are satisfied it is working, go ahead and authenticate it (it will have full functionality for 30 days without authentication). More details and step-by-step instructions at this site:

http://windowssecrets.com/comp/070201#story1