After all drivers have been installed for a soundcard, the next step is to select the soundcard as the primary audio device. This can be done by clicking on Control Panel (switch to “classic view” if you haven't already done so) and click on “Sounds and Audio Devices”. Click on “Audio”. Click on “Sound playback” and make sure that your soundcard is selected.
If you have installed your soundcard but it does not show up in “Sound playback” menu, restart your computer twice. (Yes, one should be enough, but computers are CRAZY!). If you've followed all of the instructions included with your soundcard, are sure that the device is plugged in, but your device still does not show up under the “Sound playback” menu, something is wrong. Go ahead and ask for help on the Home Recording Forum.
Also, select your soundcard in the “Sound recording” menu. Again, if it does not show up, follow the advice in the previous paragraph.
If your soundcard uses MIDI, it's a good idea to go ahead and select your Soundcard under the MIDI menu as well.
I recommend that you disable your default, integrated soundcard (assuming your computer's motherboard comes with integrated audio) and forget about it. When you have a real deal recording soundcard, there is no reason to use the piece of junk in your motherboard. It's not like you are going to wear out your fancy soundcard or anything. More importantly, if there is trouble, it's easier to troubleshoot a system with only one soundcard.

Graphic provided by DT_Chris from http://www.darktownstudios.com
F – Incoming Audio To Your Recording Software – Yes, I know that your recording software is inside your computer. However, I find it helpful to think of the software as a separate component in the signal chain.
While it's easy for most people to understand that an analog audio signal flows through a soundcard (take a look at C in my mega graphic). However, most people are not aware that the software sort of works the same way.
Because audio recording software is setup to pretty much work with any hardware (there are a few exceptions to this rule) they let you decide which inputs you want to use. If you look at the soundcard at figure C, you'll notice that it has two XLR inputs in the front. If memory servers me well, this unit has 6 1/4” inputs (like guitar cables) in the back. With a soundcard with 8 inputs, you can select any one input for a track you may be recording. With this freedom, comes the hassle of setting it every single time.
However, before you can select the specific input you want to use, you need to tell your audio recording software which soundcard it should be using. I mentioned above that it's easier to setup a home recording system with just one soundcard. Again, I recommend that you disable your default,crappy, factory soundcard as there is little need to use it when you have a real, home recording soundcard.
Regardless as to whether you keep your junky soundcard active or not, you need to select your soundcard in your audio recording software. This is where many people go wrong. People just assume that the software detects the new soundcard. This is not an unreasonable idea, but in this case you need to, at least, double check to make sure that your home recording soundcard is setup as the default input.