Please help me set up multiple monitors

Hey guys I was wondering if any of you have any idea how to set up multiple monitors i already have a inbuilt vga card and a Nvidia Geforce 9400 GT.
If i try to select any one as primary video adapter through bios the other one loses signal and no matter how hard i try, only one works.
Also Nvidia Geforce 9400 GT has two outputs vga and digital if i can find a digital to vga Adapter can i use that as a second moniter ?
And if all else fails, I want to like buy a really cheap card that would support dual monitors, any suggestions even older one’s will work.
Answer #1
AFAIK you can’t enable both on-board and normal video card , i think you can connect your video card (9400gt) to 2 monitors but it could eat you video card memory .
Answer #2
It has 1 Gb memory so that wont be too big of a problem but are you sue it can be done, it don’t want to buy an adapter just so to throw it in trash latter on.