I'm sure you have had this before people , but i just bought ASUS XONAR DX pci express souncard , and yeh , you guessed it , my compter won't recognse it , i have an acer aspire x5900 slimline pc with one free pci express slot which i have used to put the sound card in , this particular one needs power from supply unit , a "4 pin floppy" power cable which i have plugged in fine , from my coolmaster 600 watts psu.. i am on windows 7 64 bit PLLLEEEASSSSEE HELP!!!!!!!!