Inspiron 1720 seeing/using wrong graphics card?

This laptop is a few years old now and when I bought it I upgraded to the GeForce 8600M GT graphics card.

I don't play many games but at one point I had Age of Conan installed which requires a  ATI Radeon 9800/nVidia GeForce 6600

Recently I tried to install Lord of the Rings which requires a 64MB NVIDIA GeForce® 3 or ATI® Radeon® 8500 as the minimum card specs.

As far as I can tell the Lord of the Rings game should be a breeze to play by comparison but it won't even install. 

My question is:  Could my computer be using the on board graphics chip rather than the installed GeForce card?  My DxDiag file mentions the chipset as being nvidia but otherwise doesn't mention a geforce card.

 Card name: Standard VGA Graphics Adapter
 Manufacturer: (Standard display types)
 Chip type: NVIDIA

Also, I recently upgraded to Windows 7.