I have an hp pavillion dv 2500 with windows xp. The hp tag on the botton says dv2700, p/n KC450UA#ABA. It also shows dv2710us It has conexant hd smartaudio 221. The laptop came with windows vista and the previous owner installed xp pro. I am unable to adjust the bass/treble slide controls. The controls are greyed out. I don't know what to do, I've tried everything that I can think of and would appreciate any help or suggestions.