Copied from Realtek Homepage:
Driver Package R2.20
Realtek HD Audio Driver support all of Realtek HD Audio Codec in Windows Vista.
Vista WHQL Supporting:
ALC882, ALC883, ALC885, ALC888, ALC889, ALC861VD, ALC660, ALC662, ALC663, ALC665, ALC260,
ALC262,ALC267, ALC268, ALC269, ALC272, ALC273, ALC887
HDMI Device WHQL Support: ATI HDMI Devices
OS Supporting: Microsoft Windows Vista, Windows7 x86/x64
Pack with Microsoft High Definition Audio UAAV1.0a 5013 
Driver version:
Windows Vista: 6.0.1.5817
Driver Installation/Removal Procedure For Realtek High Definition Audio Codec:
=================================================================================
>
---------------------------------------
Setup Driver at first time:
---------------------------------------
Windows Vista, Windows7:
Step 1. Run the setup.exe program to start the installation. 
Step 2. Click on [Next/OK/Go] to continue the procedure. If the Windows popup 
         Windows can t verify the publisher of this driver software  message, 
        press  Install this driver software anyway  to continue the installation.
Step 3. Finally, select to restart the system and press [Finish] to complete
        the installation.
--------------------------
Update Driver:
--------------------------
Windows Vista, Windows7:
Step 1. Run setup.exe, it will remove the original driver in your system.
Step 2. Click  Next  to remove the original audio driver in your system.
Step 3. Once after the original driver removed , reboot the computer.
Step 4. Please go back to the new driver package after computer restarted.
Step 5. Run setup.exe, it will install the new audio driver then.
--------------------------
Remove Driver:
--------------------------
Windows Vista, Windows7:
Step 1. Go to StartSettingsControl Panel.
Step 2. Select [Programs] icon.
Step 3. Select [Programs and Features] icon.
Step 4. Select  Realtek HD Audio Drivers  and press [uninstall] button.
Step 5. Click on [Next/OK/Go] to finish the uninstallation.        
Step 6. At the end of the procedure, select to restart the system and press
        [Finish] to complete the uninstallation.
>
--------------------
Silent Installation:
--------------------
Run  Setup.exe /s /f2[path] /z[-rp[pathLogFile]] 
i.e. setup.exe /s /f2c:mylog.log /z[-rpC:RHDSetup.log]
--------------------
Silent Uninstallation:
--------------------
Run  Setup.exe /removeonly /s /f1[path] /f2[path] /z[-rp[pathLogFile]] 
i.e. setup.exe /removeonly /s /f1C:AudioDriverUSetup.iss /f2c:mylog.log /z[-rpC:RHDSetup.log]
Note: 1. Please update Directx version to DirectX 8.1 or above.
Changelog:
Add/Fix
1.  Driver :
Customizations.