I get ridd of Vista from my presario C750ed and install XP Prof. I manage to instal all drivers but one cannot: sound driver. In original Vista it was conexant high definition 221. I try many drivers, but still w/o results. my notebook is quiet like a grave ;-). Ones advice me to try with windows update, but all what i got are another 2 drivers (quick launch buttons and webcam). It seems that the previous drivers I tryied are not uninstalld even if I do it from device manager (I think thats why windows update not say a word about missing audio drive and come up with a valid version).