The root folder is your GTAIV folder. Do you have Dsound.dll? Also did you use the automated install or the manual install? Did you run the diagnostic program?
You may have accidentally triple posted there. Thanks Sam for the updates, I was optimistic it could be released today but take your time I would much rather have a more stable mod than a crashy one.
I find the high tones to be really annoying (some clipping) but that's normal for the LAPD so don't worry about it. Awesome job though! Also I like your Youtube videos.