I have to state this is for Intel based systems only (mainly laptops) and you would be well advised to IMAGE your disk BEFORE YOU TRY THIS just in case something happens and you cannot boot your Vista (IMAGE, IMAGE, IMAGE!!!)
Once you have your disk images precede with the following:
Backup your registry or make a restore point just in case.
Under search: regedit
Navigate to: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Servic es\
Locate: folder "iaStor"
Under "iaStor" you will find a folder named "Parameter" > delete this folder
Locate: folder "iaStorv"
Under "iaStorv" you will find a folder named "Parameter" > delete this folder