I uninstalled the chipset drivers in add remove programs in control panel. And used driver sweeper ( Like driver cleaner pro but for vista)
http://downloads.guru3d.com/download.php?det=1655
Cleaned in safe mode using nvidia chipset cleaning, rebooted and reinstalled the 15.00 driver package. Install everything you need bar the media shield and sata drivers. Vista will install them for you using the update system. Hope this works for you mate because i had a right nightmare with it. GL