1. download/install Ccleaner from Piriform. run Ccleaner > tools > startup. under Windows tab check to see any .wav files or programs that playing the sound.
2. control panel > sound > click on sounds tab > uncheck "Play Windows startup sound"
3. restart audio service, start > run > type cmd and type in these command
net stop audiosrv (Enter)
net start audiosrv (Enter)
hope it helps,
Thanks. Ccleaner didn't find any .wav files but I did the other two and errors occured. I'll mark your answer as the solution after I run my PC a bit to make sure the problem is resolved.