I have not received such a message on a Windows 2000 advanced server, but I have on a Windows 2000 pro workstation, the two general culprits are usually Service Pack levels, and Anti-virus software.
1.) What is your latest Service Pack level 2?3? Even if your server is at service pack 3, I would apply it again. (It is a microsoft product, and is not guaranteed to work the first time.)
2.) What virus protection do you have for your 2k advanced server? Net Shield or something similar? Make sure that you have all the latest patches and fixes for Virus Scan software and anything else that is running and using resources all the time (even Backup software).
Instead of using the standard Microsoft update web site, go out and download an evaluation of UpdateExpert from St. Bernard software (www.stbernard.com). This will allow you to audit and apply servie packs, hot fixes and patches from one location for up to (5) workstations or servers.
Audio-sys, does sound like the genericsystem loaded audio driver...make sure all drivers for all hardware to one extent or another are up to date.
Best of Luck!
Paul