Disable the PC Speaker beeps in 200x/XP/Vista

These commands assume administrative rights on the PC.

To temporarily disable the PC Speaker beep:
net stop beep

To disable the PC Speaker beep for good (until you undo this setting):
sc config beep start= disabled

So, if you are bothered right now by PC Speaker beeps and want them to go away even after a reboot, run net stop beep and then run sc config beep start= disabled.

The space between start= and disabled is required.