I belive it has somthing to do with the ESS sound card installation. Do you have that sound card, or did you?
My niece was removing programs and said she removed an AOL/AIM program and restarted for it to only start up in dos now with the above error command. She just got the system and Win 2000 was working fine until her action of removal.
Try the various suggetions, also try a disk defrag, and if all else fails a repair install of windows should fix it. You should not lose any data, but if you do the repair install, backup some files first.