iTunes Affecting RealTek audio

Hi,

I have just updated my itunes to the latest version. When I restart my computer i am prompted to insert the cd for new hardware relating to my speakers. These speakers are just standard ones from a supermarket which come with no installation cd as they just plug into the line-out jack on the back of my pc. When i try and load itunes i get a audio playback error message and of course....no sound.

I have never encountered this error before until I updated this time.
Arrghhh!! Anyone got any ideas? Thanks.