This is probably a newbie question but please bear with me. I have a windows xp box in which i just installed a Dynex DX-SC51 sound card. This is hooked up to my Logitech G51 speakers. While I realize that both products are somewhat "low-end" they both claim to be capable of 5.1. However, when watching a DVD in my computer I do not get true 5.1. Can someone tell me if these devices are in fact not capable of 5.1 or if there is another component or piece of software that I need in order to allow for 5.1?