hi i recently bought Compaq Presario SR1639UK Desktop PC its got Integrated 5.1 sound card, and i have creative speaker which are 5.1 .. but i just cant make all of them work at a time only two speakers will work with the woofer !! even whe i go to the audio setup where it checks each speaker individually !! , it wont give any sound from the other three. Iam pretty sure it uses Realtek AC'97 soundcard !! any suggestion guys !!