In my computer, avast! is set to not make any sound when it starts or ends, but when it does, it sounds like the default system beep (ding!). Not a major problem, but it is sometimes annoying, especially when the volume is high.
I reviewed several times the configuration of sounds, and it shouldn’t make that beep when it starts (or ends). I have no similar problems with any other program. Does anyone know why this occurs? My OS is Windows Vista Ultimate SP1.
Well, I’m only english-speaking, but it doesn’t look like what you have highlighted in your picture is the Avast sounds.
I’ve attached a pic as to what I’m referring to. See the fact that 'avast! antivirus" is shown, and there are sounds associated with it.
I know that this isn’t a screenshot from a vista machine, but I believe that the same principal should apply here.
Oh, and it sounds like you already have this checkbox enabled in your post
avast! is set to not make any sound when it starts or endsbut you can adjust your sound settings by right-clicking the avast icon in the system tray, clicking Program Settings, then clicking the sounds section. See picture.
Mmmm. Sorry, my image wasn’t clear enough. 
We’ve attached a new image.
My problem is avast! shouldn’t make any sound when it starts or ends (items “Comienzo del programa” = “Program start” and “Fin del programa” = “Program end” don’t have associate any sound: “(Ninguno)” = “b[/b]”), but it makes a beep anyhow.
All I can do is disable all sounds or associate different sounds, but I want to achieve avast! doesn’t make any sound when it starts or ends, keeping the rest of sounds. Maybe my problem is a little bug of avast!, because I think my sounds settings are correct.
Thanks.