Hi,
Before moving on, please let me know whether it is a cleanly installation or upgrade installation. If it’s a upgrade installation, please try to install Vista in Clean Boot.
I recommend you update your system BIOS to the latest version. Then, run Windows Vista Upgrade Advisor to check if there is any software or hardware incompatible product on your system.
Asus driver download:
http://support.asus.com/download/download.aspx?SLanguage=en-us
Microsoft Windows Vista Upgrade Advisor:
http://www.microsoft.com/windows/products/windowsvista/buyorupgrade/upgradeadvisor.mspx
Then, please unplugging all unnecessary hardware devices such as printer and external hard drives, and reinstall Windows Vista again.