The easiest way to set up a video wall is generally to use tile matrix mode on your displays, such that your media player connects to display #1 via HDMI or DisplayPort, display #1 connects to display #2, and so on.  

However, high-end media players like the Enterprise Quad can also divide the resolution of your content evenly among its two, three or four DisplayPort outputs so you can plug each display directly into one of the DisplayPort outputs.  In order to do that you will use the on-board AMD Radeon settings called Eyefinity:

a) Right click on the desktop and select "Radeon Settings" (There must be 2 or more screens plugged in for this to work)
b) If you have 2, 3 or 4 screens connected and still do not see "Radeon Settings" please reboot and try again

Attached is a picture showing what you should see when you select Radeon Settings - select Eyefinity on the bottom.