How do I know if my motherboard will support another video card?

I searched for a question and found that even though my video card (P.O.S.) is integrated, i can still install another into my motherboard. How do I find out if it is capable of doing this?|||See if it has an available PCI-e slot. If it has AGP then you're outta luck, since those cards can't be found anywhere except eBay or the dump. AGP card performance on newer games also suck.|||What's the name of the motherboard ? Check the manual if there is APG or PCI-E slot. You can also install PCI cards but they're pretty slow and gaming sucks.