Tech Support: Allowing or Blocking 'dontallow' Audio Device via Command Line

Tech Support: Allowing and Blocking Audio Devices via Command Line

In this article, we will discuss how to allow and block audio devices using the command line by modifying the registry key. This can be useful for troubleshooting audio issues, as well as for managing multiple audio devices on a single system.

Allowing and Blocking Audio Devices

To allow or block an audio device via the command line, you will need to modify the registry key that corresponds to that device. The following steps will guide you through this process:

1. Press the Windows key + R to open the Run dialog box.
2. Type regedit and press Enter to open the Registry Editor.
3. Navigate to the following key: HKEY\_LOCAL\_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96C-E325-11CE-BFC1-A8FF4F26A00F}
4. Under this key, you will find several subkeys, each of which corresponds to a different audio device on your system.
5. To allow or block a device, find the subkey that corresponds to that device and modify the UpperFilters or LowerFilters value.

Modifying the UpperFilters and LowerFilters Values

The UpperFilters and LowerFilters values determine which audio drivers are loaded for a particular device. To allow or block a device, you will need to modify one of these values.

To modify a value, right-click on it and select Modify. In the Value data field, you can add or remove drivers by separating them with a semicolon (;). For example, to allow the Realtek High Definition Audio driver, you would add RealtekHDAudio to the value. To block the driver, you would simply remove it from the value.

Here is an example of how you might modify the UpperFilters value to allow or block the Realtek High Definition Audio driver:

UpperFilters = RealtekHDAudio;msudclnx;msudc;usbvideo

Using the Command Line

You can also modify the registry key using the command line. To do this, you will need to use the reg command. Here is an example of how you might use the reg command to allow the Realtek High Definition Audio driver:

reg add HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E96C-E325-11CE-BFC1-A8FF4F26A00F}\0000 /v UpperFilters /t REG\_SZ /d RealtekHDAudio\;msudclnx\;msudc\;usbvideo /f

To block the driver, you would simply remove it from the value:

reg add HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E96C-E325-11CE-BFC1-A8FF4F26A00F}\0000 /v UpperFilters /t REG\_SZ /d msudclnx\;msudc\;usbvideo /f

In this article, we have discussed how to allow and block audio devices using the command line by modifying the registry key. This can be a useful troubleshooting technique, as well as a way to manage multiple audio devices on a single system.

References

• Microsoft: Audio hardware and the registry
• Microsoft: Upper filters and lower filters
• Microsoft: Command-line options for reg