Ok! now I got my account and my registration problem are out, I can reply !
So I had exactly the same problem as this poor guy and it's quite frustrating... but I found the solution:
it sounds crazy but it's "accesibility" related !
go to the control panel -> accesibility options -> sounds
and uncheck "use Sound sentry" (or any accessibility options maybe)
that should do the trick
ps: sorry that I didn't reply sooner