nVidia sound drivers wont load

...It's the strangest thing. I get the nVidia boot up screen. It then asks me to 'insert win98 cd into drive selected below' (when in fact there is actually no drive selected). So I put in win 98cd press enter and then it tells me 'I have decided to cancel installation of nvidia drivers and will cancel setup' - then BSOD, no drivers = no sound. What's going on? (All the other drivers on the same Asus disc load with no problem).