can you explain more the issue , and please what you mean by "MS-DOS audio problems" ,Windows 2000 have NT 5 kernel not MS-DOS based ,
if you have the driver installed so if the speaker icon not appear in the taskbar and there are sound ,
and if you mean by " why the speaker(on volume) isn't there?" >>>
you should to enable it in control panel >> sounds and multimedia
and if you mean by : "why the speaker(on volume) isn't there?" no sound work , so there are problem in the driver installed or something related , like maybe you need to install KB888111 update for 2000/XP