If you put the computer to sleep or into hibernation when it is running on AC power, the high definition (HD) audio controller continues to use power. Additionally, even after the computer transitions to DC power while the computer is asleep or in hibernation, the HD audio controller still uses power. This behavior persists even though you disable the "Allow this device to wake the computer" option in the HD audio controller properties. A supported hotfix is available from Microsoft. However, customers facing problems, need to contact Microsoft and get the hotfix, explained Microsoft via KB970030.