I got problem installing VS2008. After narrowing down the issue, I found the
WCF is unable to be installed. Here's the detail in Event Log:

System.TypeInitializationException: The type initializer for
'System.ServiceModel.Install.IisHelper' threw an exception. --->
System.Runtime.InteropServices.COMException (0x80040154): Retrieving the COM
class factory for component with CLSID {2B72133B-3F5B-4602-8952-803546CE3344}
failed due to the following error: 80040154.
  at
Microsoft.Web.Administration.ConfigurationManager.CreateNewAdminManager(WebConfigurationMap webConfigMap, String configPathToEdit, Boolean isAdminConfig)
  at
Microsoft.Web.Administration.ConfigurationManager.GetApplicationHostConfiguration()
  at
Microsoft.Web.Administration.ServerManager.GetApplicationHostConfiguration()
  at
System.ServiceModel.Install.Configuration.IIS7ConfigurationLoader.CheckApplicationHostInstalled()
  at System.ServiceModel.Install.IisHelper..cctor()
  --- End of inner exception stack trace ---
  at Microsoft.Tools.ServiceModel.CommandArguments..ctor(String[] args)
  at Microsoft.Tools.ServiceModel.ServiceModelReg.Run(String[] args)
  at Microsoft.Tools.ServiceModel.ServiceModelReg.TryRun(String[] args)

and the log (dd_wcf_ret*.txt) is below:

[11/26/07,10:25:45] ========== Logging started ==========
[11/26/07,10:25:45] =====================================
[11/26/07,10:25:45] No language specified in ini file default to OS language
[11/26/07,10:25:45] Set lang to 1033
[11/26/07,10:25:45]  Pending Reboot Table state : Logging start
[11/26/07,10:25:45]    _________________________________________
[11/26/07,10:25:46] (, ) c:\f54d9e339d54c2cb19ee641450e7   (  ----  )   (
Mon Nov 26 09:38:22 2007 )     Delete
[11/26/07,10:25:46] (, ) c:\ca174613ec57bb488ad113   (  ----  )   ( Mon Nov
26 10:25:41 2007 )     Delete
[11/26/07,10:25:46]  Pending Reboot Table state : Logging end
[11/26/07,10:25:46]    _________________________________________
[11/26/07,10:25:46] Logging property values
[11/26/07,10:25:46] PROPERTY    ProductName    Windows Communication Foundation
[11/26/07,10:25:46] PROPERTY        c:\0df929f3873754e8eea678505c9b\wcf.msi
[11/26/07,10:25:46] PROPERTY    ProductMsi    wcf.msi
[11/26/07,10:25:46] PROPERTY    Ini
Filename    c:\0df929f3873754e8eea678505c9b\install.ini
[11/26/07,10:25:46] PROPERTY    ProductCode   
[11/26/07,10:25:46] PROPERTY    ProductRegKey   
[11/26/07,10:25:46] PROPERTY    ProductRegValue   
[11/26/07,10:25:46] PROPERTY    ProductRegData   
[11/26/07,10:25:46]
PROPERTY    ProductSupportURL    http://go.microsoft.com/fwlink/?LinkId=12975
[11/26/07,10:25:46] PROPERTY    DefaultDirInstallToken   
[11/26/07,10:25:46] PROPERTY    Install   
[11/26/07,10:25:46] PROPERTY    SupportWin9X    0
[11/26/07,10:25:46] PROPERTY    MinNTVersion    5.0
[11/26/07,10:25:46] PROPERTY    CheckAdminRights    1
[11/26/07,10:25:46] PROPERTY    BlockOn64Platform   
[11/26/07,10:25:46] PROPERTY    ShowFeatureOptions    0
[11/26/07,10:25:46] PROPERTY    ShowDestinationFolder    0
[11/26/07,10:25:46] PROPERTY    LogFilePrefix    dd_wcf_ret
[11/26/07,10:25:46] PROPERTY    CustomTextPrefix   
[11/26/07,10:25:46] PROPERTY    MSI Log
name    C:\DOCUME~1\ADMINI~1.DON\LOCALS~1\Temp\dd_wcf_retMSI3FA5.txt
[11/26/07,10:25:46] PROPERTY    Msi Command Line properties   
[11/26/07,10:25:46] PROPERTY    VerboseLog    1
[11/26/07,10:25:46] PROPERTY    RebootMode    1
[11/26/07,10:25:46] PROPERTY    UILanguage    1033
[11/26/07,10:25:46]
PROPERTY    BitmapFile    c:\0df929f3873754e8eea678505c9b\msgbus.bmp
[11/26/07,10:25:46] PROPERTY    User Canceled    0
[11/26/07,10:25:46] PROPERTY    Red   
[11/26/07,10:25:46] PROPERTY    Green   
[11/26/07,10:25:46] PROPERTY    Blue   
[11/26/07,10:25:46] PROPERTY    Current Dir    c:\0df929f3873754e8eea678505c9b\
[11/26/07,10:25:46] PROPERTY    Temp Dir    C:\DOCUME~1\ADMINI~1.DON\LOCALS~1\Temp\
[11/26/07,10:25:46] PROPERTY    Usage Mode    0
[11/26/07,10:25:46] PROPERTY    Admin Mode    0
[11/26/07,10:25:46] PROPERTY    Maintenance Mode   
[11/26/07,10:25:46] PROPERTY    Silent Mode    0
[11/26/07,10:25:46] PROPERTY    Silent Mode Uninstall    0
[11/26/07,10:25:46] PROPERTY    WatsonSilent    0
[11/26/07,10:25:46] PROPERTY    WatsonUI    0
[11/26/07,10:25:46] PROPERTY    Silent Mode UI string   
[11/26/07,10:25:46] PROPERTY    SkipAllChecks    0
[11/26/07,10:25:46] PROPERTY    WatsonGenerateManifestOnly   
[11/26/07,10:25:46] PROPERTY    UninstallWarning   
[11/26/07,10:25:46] PROPERTY    ControlMSIService   
[11/26/07,10:25:46] PROPERTY    RTL Language    0
[11/26/07,10:25:46] PROPERTY    PostSetupCommandRegKey   
[11/26/07,10:25:46] PROPERTY    GlobDataINIPresent   
[11/26/07,10:25:46] Checking Windows Installer version...
[11/26/07,10:25:46] msi.dll loaded ok
[11/26/07,10:25:46] Looking for: 2.0.0
[11/26/07,10:25:46] Found: 3.1.4000
[11/26/07,10:25:46] Windows Installer version ok
[11/26/07,10:25:46] Finished Checking Windows Installer version. Return code 0
[11/26/07,10:25:46] Entering CMsiInstaller::ThreadInit
[11/26/07,10:25:46] Leaving CMsiInstaller::ThreadInit
[11/26/07,10:25:46] Checking Windows Installer version...
[11/26/07,10:25:46] msi.dll loaded ok
[11/26/07,10:25:46] Looking for: 2.0.0
[11/26/07,10:25:46] Found: 3.1.4000
[11/26/07,10:25:46] Windows Installer version ok
[11/26/07,10:25:46] Finished Checking Windows Installer version. Return code 0
[11/26/07,10:25:46] Entering  CNavigator::Start
[11/26/07,10:25:46] Running all checks
[11/26/07,10:25:46] Running system checks
[11/26/07,10:25:46] SYSTEM CHECK:    : One instance of setup running        Passed
[11/26/07,10:25:46] SYSTEM CHECK:    : Administrative rights check        Passed
[11/26/07,10:25:46] SYSTEM CHECK:    : Minimum NT Version 5.0        Passed
[11/26/07,10:25:46] SYSTEM CHECK:    : Not runing on 9x check        Passed
[11/26/07,10:25:46] Running prereq checks
[11/26/07,10:25:46] PREREQ CHECK:    : Windows XP Service Pack 2        Passed
[11/26/07,10:25:46] PREREQ CHECK:    : Microsoft .NET Framework 2.0        Passed
[11/26/07,10:25:46] PREREQ CHECKS:        Passed
[11/26/07,10:25:46] Running block checks
[11/26/07,10:25:46] BETA CHECK:            Passed
[11/26/07,10:25:46] Entering CNavigator::WindowCreation
[11/26/07,10:25:46] Entering CNavigator::LoadPages
[11/26/07,10:25:46] Entering CMsiInstaller::IsInstalled
[11/26/07,10:25:46] Entering CMsiInstaller::GetProductCode
[11/26/07,10:25:46] Leaving CMsiInstaller::GetProductCode
[11/26/07,10:25:46] Leaving CMsiInstaller::IsInstalled
[11/26/07,10:25:46] Created Page:    Welcome Page
[11/26/07,10:25:46] Created Page:    EULA Page
[11/26/07,10:25:46] Created Page:    Progress Page
[11/26/07,10:25:46] Created Page:    Final Page
[11/26/07,10:25:46] Leaving CNavigator::LoadPages
[11/26/07,10:25:46] Entering CMsiInstaller::RegisterUIInterfaces
[11/26/07,10:25:46] Leaving CMsiInstaller::RegisterUIInterfaces
[11/26/07,10:25:47] Entering CMsiInstaller::StartInitialization
[11/26/07,10:25:47] Leaving CMsiInstaller::StartInitialization
[11/26/07,10:25:47] Entering CMsiInstaller::InitSequence
[11/26/07,10:25:47] Entering CNavigator::Next
[11/26/07,10:25:47] Leaving CNavigator::Next
[11/26/07,10:25:47] Leaving CMsiInstaller::InitSequence
[11/26/07,10:25:48] Entering CNavigator::Next
[11/26/07,10:25:48] Entering CMsiInstaller::BeginInstall
[11/26/07,10:25:49] MsiInstallProduct called with Command line:
[11/26/07,10:25:49] USING_EXUIH=1 REBOOT=ReallySuppress FILESINUSETEXT=""
[11/26/07,10:25:52] Entering CNavigator::Next
[11/26/07,10:25:52] Leaving CNavigator::Next
[11/26/07,10:25:58] ***ERROR EVENT*** : Custom Action Failure:Action ended
10:25:58: InstallFinalize. Return value 3..
[11/26/07,10:25:58] ***ERROR EVENT*** : See Windows Install log  for details.
[11/26/07,10:26:03] ***ERROR EVENT*** : Custom Action Failure:Action ended
10:26:03: INSTALL. Return value 3..
[11/26/07,10:26:03] ***ERROR EVENT*** : See Windows Install log  for details.
[11/26/07,10:26:03] Entering CMsiInstaller::SuppressReboot
[11/26/07,10:26:03] Leaving CMsiInstaller::SuppressReboot
[11/26/07,10:26:03] Entering CNavigator::Next
[11/26/07,10:26:03] Leaving CNavigator::Next
[11/26/07,10:26:05] Entering CFinalPage::Cancel. - Post Quit message to UI
thread
[11/26/07,10:26:05] Entering CNavigator::OnDestroy
[11/26/07,10:26:05] Making synchronous call to worker to stop
[11/26/07,10:26:05] Entering CMsiInstaller::Stop
[11/26/07,10:26:05] Leaving CMsiInstaller::WorkerThread
[11/26/07,10:26:05] Leaving CMsiInstaller::Stop
[11/26/07,10:26:05] Leaving CNavigator::OnDestroy
[11/26/07,10:26:05] Leaving CNavigator::WindowCreation
[11/26/07,10:26:05] Leaving  CNavigator::Start
[11/26/07,10:26:05] Process returning code 1603
[11/26/07,10:26:05]  Pending Reboot Table state : Logging start
[11/26/07,10:26:05]    _________________________________________
[11/26/07,10:26:05] (, ) c:\f54d9e339d54c2cb19ee641450e7   (  ----  )   (
Mon Nov 26 09:38:22 2007 )     Delete
[11/26/07,10:26:05] (, ) c:\ca174613ec57bb488ad113   (  ----  )   ( Mon Nov
26 10:25:41 2007 )     Delete
[11/26/07,10:26:05]  Pending Reboot Table state : Logging end
[11/26/07,10:26:05]    _________________________________________
[11/26/07,10:26:05] =========== Logging ended ===========
[11/26/07,10:26:05] =====================================
[11/26/07,10:26:05]  
[11/26/07,10:26:05]  
[11/26/07,10:26:05]  

Any idea? Thanks in advance!