Question : Problem: Adding three monitors to one vidoe card, and expand the desktop

I need to add three monitors to a desktop, but here's the thing. I have one GEForce video card (new) with 2 ports (DVI and VGA) I can get 2 to work perfectly but I can't get the system to see the other monitor. How do I about making the system see the other monitor. I do have a internal on-board Video card, and that see' s the three monitor, but I can't get the extend the desktop to work. When I click the Apply button, it just reverts back to defualt settings and I can;t change anything. According to GeForce, I have to have the on-board Vidoe card disable for the new card tro work. I really have to have the three monitors working, in Extend mode. I could really use help.

Answer : Problem: Adding three monitors to one vidoe card, and expand the desktop

A Y cable will NOT split a video output to two monitors unless you want two identical displays.

If you want 3 monitors, you'll need either a 2nd video card, or a multi-monitor card designed for 4 or more monitors [such as one of the Matrox or Colorgraphics models ... you can see a few examples here:
http://www.multiplemonitors.org/Pages%20-%20Hardware/Hardware%20-%20Multi%20head%20Video%20cards.html

Alternative approaches to supporting more than 2 displays:

(1)  Use two graphics cards [either a 2nd PCI card or, if your motherboard has dual PCIe x16 slots, two PCIe cards.

(2)  Use a Matrox dual-head-to-go (or triple-head-to-go) adapter on one of your outputs to split it into two monitors  [the single output from the other port will then give you a total of 3 monitors].

(3)  Use a USB video adapter to support the 3rd monitor [e.g. one of these:  http://www.usbgear.com/computer_cable_details.cfm?sku=USBG-SVGA3&cats=169&catid=125%2C106%2C169