A high definition audio (HDA) device may no longer work after you resume a Windows Vista-based computer from hibernation or from sleep. The HDA device may be a sound device or a modem. You may see an “X” character appear on the speaker icon in the notification area.

Because of this problem, you no longer hear any sound. Or, you cannot use the modem. This problem occurs even though you have installed the update that is described in Microsoft Knowledge Base article 929685. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

929685 A high definition audio device may no longer work after you resume Windows Vista from hibernation or from sleep