You may have only installed the audio drivers for the card (when it auto-detects the hardware). Aark manager software also needs to be installed.
If you are installing off the Aardvark CD, simply go to the CD and run the install program.
If you've downloaded the drivers, run the makedisk program, create a directory for the Aardvark install software (this is just the installer program), possibly c:\aardvark. Then, go to that directory by going through My Computer and C: drive, and run setup from there.