1) KJ387AA#ABA comes up as an HP Pavilion a6403w desktop computer,http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&objectID=c01412768&jumpid=reg_R1002_USEN
2) Uses the Foxconn MCP73M01H1 motherboard,http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c01357119
Looking at the photo of the motherboard, observe the aluminum finned heatsink in the middle of the board, with Foxconn on it.
(Northbridge chip is under heatsink)
The long black slot below it is where a graphics card goes.
(Video card or Graphics card, same/same)
It is a PCI-Express x16 slot. A PCI Express graphics card goes here.
(The Locking Arm on the PCI Express x16 slot, looks as though you press down on it, to unlock. You don't. Gently pull up a little to install or remove a graphics/video card)
The white long PCI slot at the bottom can also be used for a graphics/video card.
If there is no video/graphics card in either of these expansion slots, you are using Integrated Graphics. The graphics from the motherboard, and not a graphics (Video) card.
Integrated Graphics is also known as OnBoard Graphics.
ON the motherBOARD.This is from an Nvidia GeForce 7100 graphics chipset.
(Sits under that aluminum heatsink with Foxconn on it)
If you are using the Integrated Graphics of the motherboard, you have a VGA monitor plugged into the blue VGA port, number 4,http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c01357119
(Scroll down to Back I/O Ports)
or you have a flat LCD screen monitor plugged into the white DVI port, number 16.
For additional questions please post in a Comment.