Creative is very picky about having the correct driver and software for the exact model of card you have.
There is something like 40 different models of the X-Fi card. Some even use the older audigy 2 chip and do most of the tasks in software while others have a actual X-fi chip in them.
Go to creative lab's site and pick out and download the driver and software. There is also a autodetect thing too.
It's also buggy with certain items hidden in various locations just to frustrate you in some sort of creative labs tradition.
Once it's installed you will have no sound. Why? Oh because it defaults with digital out .
Then everything is set to the wrong bitrate. Go and set most items to the standard 16bit 44100Hz that is standard in most mp3's, cd's and video including hdmi and hdtv. Forcing everything to convert bitrates on the fly and also going from 24bit to 16 bit causes lag and distortion.
But the mic and some line in's only support 48000hz, it seems to work ok that way.
Now the sound works but no sub right? Go to the speakers in the control panel in windows. un-click the smaller speakers so they are not "Full range speakers" and 5.1 or what you need.
Then open creative lab's audiorack and select bass redirection.
If you need more bass enable the 15db gain box. Then go into sound in windows control panel and speakers in properties there is a levels tab. You can adjust the sub down so it's more bass than default but not too much. I found the 15db box clicked on and the level at 60% works well.
Also the Crystalizer is set too high so set it to about 30%.
If not all the speakers work, in creative's console enable CMSS-3D surround.
I found using the game mode is the best.
-If you want to record the sound you hear, enable "what you hear" in sound. I found it distorts so i set the level to 21%. You will just have to see what the meters look like in the Creative Wavestudio.
It works with msi afterburner too.