NFSMW not working in Vista 64-bit

[Gryphon22]

The game refuses to install telling me that I need DirectX 9.0c or higher even though I am running the newest DirectX. Anyone know how I can get this to install? I am running a completely new system and have had no problem installing any of my other games, so far. My specifications are:

Asus Maximus Formula Motherboard Intel X38 Chipset(Rev. 342.01)
Intel Core 2 Quad Core Q6600 2.4Ghz Kentsfield
nVidia GeForce 8800GT 512MB(Ver. 6912 Beta)
4 Gigs of DDR2 RAM
Creative X-Fi Xtreme Audio(Ver. 1.04.0078)
DirectX 10
Windows Vista Home Premium 64-bit

The only possibility I can think of is the nVidia beta drivers I am using, but I wouldn't think that would make the game think I didn't have a correct version of DirectX. If anyone can help me figure this out it would be much appreciated.