What are usual maximum output frequencies on computer sound cards?

Can I have two sound cards on my computer? One playing itunes the other playing regular stuff that I surf?

• I have a laptop that has an integrated sound card. If I plug an aux output to my office sound system, I can play music via itunes and stream it onto the office sound system. Of course the integrated speakers are shut down automatically when I plug in the aux input into the headphones plug. The down side is that if I surf onto websites that use sound like youtube, the whole office hears the sound blended in with the office music. If I buy an external usb sound card, can I direct itunes to use that sound card instead of the integreated soundcard/speakers and therefore have a computer with two different sound ouputs at the same time?

• Answer:

  Windows typically doesn't like to have 2 soundcards functioning at once. A better plan would be to get a soundcard with 4 channels, and then route WAV playback to 3/4 and keep everything else on 1/2.