660M 2gb Nvidia installed in M17X R3 and now computer is running slow

I bought an M17x R3 Alienware laptop recently, and after I tried to play Star wars of the Old Republic, the game would not play. After seeking help on this issue, I was told that my graphics card is not fast enough to keep up with the startup of this game and suggested that I install an Nvidia card. I bought an Nvidia card and installed it(realizing that an Nvidia card was ALREADY installed) After startup the computer is running extremely slow. I took the computer to get it checked out and they said they are unable to fix the issue. I am not sure if the correct driver needs to be installed, or if it's a bad card, or if its not compatible with my laptop. can someone shed some light on this issue please?

I don't know exactly. Under Device Manager it says "Standard VGA graphics adapter". It said the same thing when my previous graphics card was in, and they said I needed to install an Nvidia card(which was already installed)

belated reply on this, simple solution to your problem. Your Alienware is picking up the on board card instead of the Nvidia card you have installed. You can switch the on board card off via bios, by pressing F2 on startup. Switch from SG (standard graphics) to PEG(PCI enabled graphics). Save and exit, then presto, you are now running your Nvidia card. Of course you will then need to install the correct drivers to run the card. Quite often with later nvidia cards on the R3 series a modified .inf file is needed.