I recently got a new latitude d630 and a pet peave it brought with it was an very loud and annoying system beep if I typed my password wrong.  If you run into this on a different laptop, you’ll probably also have luck trying to disable a Hidden Device in Device Manager.

Its called "Beep" and its under "Non-PLug and Play devices" , it hidden so make sure to select view hidden devices.

Very Clever MS :p