After you install Windows Vista Service Pack 1 (SP1), you may experience one or more of the following problems with sound:

•	No sound is produced when you play audio files or run programs that have an audio component.
•	The speaker symbol next to the clock in the notification area may display the following message: No Audio Output Device is installed
•	The Sound Controller in Device Manager displays a yellow exclamation point.

Back to the top

Changes to Sound Behavoir may occur because Windows Vista SP1 updates system files and many inbox device drivers to improve device reliability. To do this, the service pack will reinstall many device drivers at the end of the installation process. Some older drivers may experience an installation failure because of this process.

Note We recommend that you install the latest drivers for your hardware before you install Windows Vista SP1. When you do this, you can help avoid the problem that is mentioned in the “Symptoms” section.

Back to the top

To resolve this problem, use the following methods in the order in which they are presented. After you try each method, determine whether you can hear sound. To do this, play an audio file by using a program such as Windows Media Player.

Note Remember to turn the volume up on the computer speakers and on the program volume control.

Back to the top

Method 1: Restart the computer

It is important to restart the computer at least one time after you install Windows Vista SP1 to verify that all related processes are complete. These processes include driver installations.

After you restart the computer, determine whether you can hear sound.

Back to the top

Method 2: Plug the computer speakers in again

Most sound cards that are compatible with Windows Vista include a feature that detects the audio jack into which the speakers are plugged. You may have to unplug the computer speakers from the sound card and then plug them back in to the same port. This procedure may enable the audio detection feature to configure the output device.

Back to the top

Method 3: Verify that the default output device is set correctly

After you install Windows Vista SP1, you may find that the default output device, also known as the playback device, has changed.

To set the default device, follow these steps:

1.	Click Start, type Sound in the Start Search box, and then click Sound in the search results at the top of the Start menu.
2.	Click the Playback tab. A check mark is displayed next to the default device. For most users, the default device is Speakers.
3.	Click the item that you want to set as the default device, and then click Set Default.
4.	Click OK to save your settings and to close the Sound dialog box.

Back to the top

Method 4: Verify that the sound driver is installed

To do this, follow these steps:

1.	Click Start, type Device Manager in the Start Search box, and then press ENTER.
2.	In the Device Manager dialog box, expand Sound, video, and game controllers. If there is a yellow question mark next to an item in the list, the device driver is not present or will not load. Go to Method 5.

Back to the top

Method 5: Reload the current sound driver

To do this, follow these steps:

1.	Click Start, type Device Manager in the Start Search box, and then press ENTER.
2.	In the Device Manager dialog box, expand Sound, video, and game controllers.
3.	Locate the audio device that was included with the computer.
4.	Right-click the device, and then click Properties.
5.	Click the Driver tab.
6.	Click Uninstall.
7.	Make sure that the Delete the Driver Software for this device check box is cleared, and then click OK.
8.	In the Device Manager dialog box, click the Action menu, and then click Scan for hardware changes. You should see a message that a hardware device is being installed. Additionally, the uninstalled audio device is now present in Device Manager.
9.	Close the Device Manager dialog box, and then determine whether you can hear sound.

Back to the top

Method 6: Update the current sound driver

To do this, contact the manufacturer of the sound driver to request an updated sound driver.

Note In some cases, the manufacturer may instruct you to uninstall the current sound driver and to delete the driver files. To do this, follow the steps in Method 5, but at step 7, click to select the Delete the Driver Software for this device check box.

For information about how to contact hardware and software vendors, click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

Back to the top

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Back to the top

For more information about how to resolve common sound problems in Windows Vista, visit the following Microsoft Web site:

Back to the top