I dumped Crescendo; it screwed up my other settings and was more trouble than it was worth from my point of view. Incidentally, changing file associations via Explorer will not prevent unwanted applications from opening soundfiles accessed through a non-Microsoft browser; you have to adjust the settings in the application itself as well. With Quicktime, I forbade it to play midis or aiff files; Netscape's unobtrusive native plugin is perfectly capable of handling these. I have no idea what plays midis in Opera; presumably a native plugin. It keeps itself to itself, at any rate.