Disable Integrated Graphics Card in Bios

I bought a Alienware m17 6877 (link here: http://www.amazon.com/Alienware-ALW17-6877sLV-17-Inch-Gaming-Laptop/dp/B00F4MEGBI/ref=sr_1_8?ie=UTF8&qid=1393472713&sr=8-8&keywords=alienware+m17x) from Amazon. The specs are listed there. 

First thing I did once I booted to windows was to update all the display drivers. Naturally, I downloaded the drivers from NVIDIA. Little did I realize that once I did this, the Function Key responsible for disabling/enabling Integrated Graphics card doesn't work. In this regard, I have a 3-part question

1. How do I undo the damage done above?

2. How do  I know what graphics card I am using [Integrated/Discrete]? Is there are command line utility to find this out [it would be great if I know this for both Windows and Linux].

3. How do I permanently shut down Integrated graphics [force the computer to always use discrete graphics card] in the Bios so that it will never trouble me again.