I just bought a new HP desktop that has Realtek audio. I cannot get any sound and have tried different speakers and headphones. Still no sound. All volume controls are on high. Spent 2 hours on phone with HP tech support, no solution. Information balloon keeps flashing on and off in system tray "you just undplugged a device into the audio jack" and "you just plugged a device into the audio jack" when I am not plugging or unplugging anything! Help!