No Sound... Multimedia Audio Controller Issue

Question

   I have an Asus P4S800-MX Motherboard which doesnt play any sound since I upgraded it to Windows XP Media Edition 2002. The computer is an Intel Celeron with a 2.67GHz processor.

   I have my speakers plugged it but when I try to open a sound via e.g. iTunes it says 'There is a problem with you Audio/Video Configuration'
   On my control panel I went to System > Hardware > Device Manager and next to my Multimedia/Audio Controller a yellow '?' has appeared.

                               Any Help Most Appreciated!I have apackard bell notebook which doesnt play any sound since I upgraded it to Windows XP . The computer is an Intel Celeron m with a 1.4 GHz processor. I have my speakers plugged it but when I try to open a sound via e.g. iTunes it says 'There is a problem with you Audio/Video Configuration' On my control panel I went to System > Hardware > Device Manager and next to my Multimedia/Audio Controller a yellow '?' has appeared. Any Help Most Appreciated!