How can I set up dual monitors with nVidia?

I just got a new computer (W520, Graphics card nVidia GF106 [Quadro 2000]) and installed ubuntu on it using wubi. I have everything working, so I wanted to set it up to be able to use two monitors with an extended screen. I figured I had to edit Xorg.conf, but the file didnt exist. So I tried to create it by booting in recovery mode, and executing

 Xorg -configure

but I am getting these errors:

(EE) Failed to load module "vmwgfx" (module does not exist, 0)
(EE) vmware: Please ignore the above warnings about not being able to load module/driver vmwgfx
(++) Using config file: "/root/xorg.conf.new"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(EE) [drm] No DRICreatedPCIBusID symbol
Number of created screens does not match number of detected devices.
    Configuration failed.
  ddxSigGiveUp: Closing log

Any idea how I can get Xorg -configure to work, so that I can have an xorg.conf file that I can edit to enable twinview?

Why can't I boot with an xorg.conf file generated by nvidia-xconfig? Is there something in the generated xorg.conf file that might need editing?

I have an nVidia Optimus technology which seems like it precludes me from running Unity 3d. Can I have dual monitors while running unity 2d?

You shouldn't really need to worry about xorg.conf. You need to install your nvidia drivers. The first thing you need to do is login normally, hit SuperKey and type in: Additional DriversOpen the Additional Drivers. You should see the following:

Select the one of your choice, and hit activate. The drivers should download for you, and install. Once the download/installation is complete, it will let you know that you will need to restart.

Once restarted you should then have access to the Nvidia X Server Settigns Application. You'll be able to find it by hitting SuperKey again and typing in: nvidia

You can then go to:

Hit Detect Displays, Set the Resolution, and Twinview or with one of your displays (whichever you prefer) set to primary.

I have access to a W520 at work. Let me know if this helps or if you need a little more info and I'll try to see what I can do to add more detail.