I used to have the same problem with Win2k Advanced Server. Do several things...run Windows Update, download whatever Service Packs and updates you need. If that doesn't fix things, pull out the sound card, clean the little PCI contacts and blow into the slot (unless you're brave enough to shove Q-tips in there), and make sure the card is seated firmly.
If that doesn't work...contact your administrator <smirk>
Hey man, I bet your video card driver is causing this problem & I'd guess you're using one of nvidia's latest reference drivers. Does the memory dump happen randomly or only when your using the same type of program (media players for example)?
Go to http://www.reactorcritical.com/download.shtml & download a slightly older driver version (like the 6.18, 6.27 or 6.31) for your card & see if that fixes your problem. Let me know how it works out.
P.S Make sure you "properly" remove the current drivers (remove in "add/remove programs", select standard pci adapter & reboot) before installing the new driver.