Pulseaudio Daemon Startup Failed
Running
pulseaudio -v
in a terminal (run pulseaudio -k first if it complains about already being started, but since you say it doesn't work, it most probably is not running. Prefix sudo if it complains about permissions) should get you more detailed output on why PulseAudio won't start, which will enable you to find more specific info in your case.
If the error message is not clear enough, just keep adding v:s, e.g.
pulseaudio -vvvv