Two days ago all sound and audio functions crapped on my Dell M415 Vista SP1 computer. Every check I do says the board is working fine. I have uninstalled and reinstalled drivers anyway. At boot, prior to the login, the windows sound plays fine through the speakers/ Once the system is booted there is nothing. WMP gives an error that it cannot access files. NO audio player will play the files that previously worked fine. This is all types of audio (mp3 wav internet functioning). I can play videos but there is no sound. I had installed Windows recent updates, so I even tried uninstalling those to no avail. The CD player will not play CDs (obviously because the computer recognizes nothing audio). Ran virus check twice and it turned up nothing. And yes, I checked jacks and wiring (which of course would not explain how the boot sound ALWAYS comes through fine). I also stopped EVERY boot startup program to see if that would help (NO). I am totally lost as to where to go for help or how to proceed. Can someone help me?