Close process in nsis script during install

I plug "nsProcess" to close the program, but when I close the program is running, a message will appear in the "Are you sure? OK - Cancel"! How can I automatically during installation option chosen Yes, without direct user intervention?

${nsProcess::CloseProcess} "yahoomessanger.exe" $R0

You wouldn't by any chance be installing one of those smiley packs that come with complimentary browser hijacking?