Yes it all installs on your system.
If you have an aftermarket soundcard you'll want to disable the Realtek though = in bios.
Or uninstall it = i did.
You have to choose one as a default device for whatever you're doing via the volume icon control.
They're unrelated processors that can both handle your system's sound. The Realtek is the one built into your motherboard, and the Audigy is a discrete card. Both will probably work with whatever hardware you have, but they cannot both work at the same time.
^^ Technically, you *can* if the software allows you to manually select a non-default output device. Though *some* companies write their drivers in such a way so they break in really odd ways if another output device is installed...