Here was the situation. The computer had been overcome by a virus, which I got rid of with help. And in doing so at some point at start-up, just before sign-in or logon, a beep would sound.
It really wasn’t a big deal. And everything I read said that it meant everything was functioning properly. But the person whose computer this was would buy another computer rather than deal with that loud beep every time the computer started up.
In googling dell inspiron 1520 loud single beep users logon, I came across this.
There is a setting in device manager. (Go to My Computer, right-click, choose properties, then hardware, then Device Manager)
Under device manager, in the menu choices click on view.
Click Show hidden devices.
Click Non-plug and play.
Right-click Beep. Select Disable.
You will receive a warning. Press OK. Then it will suggest you restart.
Then, voila! Beep gone. Good one. Thanks, jshadoww.