COMException from WPF applications after .NET Framework 4.7 is installed on Windows 7 or Windows Server 2008 R2

This article helps you resolve the problem where System.Runtime.InteropServices.COMException occurs in Windows Presentation Framework (WPF) applications.

Original product version:   .NET Framework 4.7, Windows 7 Service Pack 1, Windows Server 2008 R2 Service Pack 1
Original KB number:   4033488


Consider the following scenario:

In this scenario, the WPF applications fail and generate error messages:

Exception type: System.TypeInitializationException
Message: The type initializer for 'MS.Win32.Penimc.UnsafeNativeMethods' threw an exception.
InnerException: System.Runtime.InteropServices.COMException
Message of the inner exception: Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))


To resolve this problem, install the July 25, 2017, update for the .NET Framework 4.6, 4.6.1, 4.6.2, and 4.7 from the Microsoft Update Catalog.


To work around this problem, uninstall and then reinstall the .NET Framework 4.7. Alternatively, temporarily disable the affected WPF touch component.

Uninstall the .NET Framework 4.7

  1. In Control Panel, select Uninstall a program in the Programs category.

  2. In the list of programs, locate and select Microsoft .NET Framework 4.7, and then select Uninstall/Change.

  3. In the .NET Framework 4.7 Maintenance wizard, select Remove.NET Framework 4.7 from this computer, and then select Next.

  4. If the following warning window appears, select Continue.

    Screenshot of the warning window, which shows uninstalling Microsoft .NET Framework may cause some applications to cease to function.

  5. Wait for the uninstallation to complete.

Reinstall the .NET Framework 4.7

To reinstall the Microsoft .NET Framework 4.7, use one of the following methods.

Method 1: Manually download and install the .NET Framework 4.7

  1. Download the web installer for the .NET Framework 4.7.
  2. Install the .NET Framework 4.7.

Method 2: Use Windows Update to install the .NET Framework 4.7

  1. Open Windows Update.

  2. Select Check online for updates from Windows Update.

  3. After the search for updates is complete, select Optional Updates available.

    Screenshot of the Windows Update panel, showing the link of optional updates available.

  4. Locate and select Microsoft .NET Framework 4.7 for Windows 7 and Windows Server 2008 R2, and then select OK.

    Screenshot shows the optional updates, where Microsoft .NET Framework 4.7 for Windows 7 and Windows Server 2008 R2 for x64 (KB3186497) is selected.

  5. Wait for the installation to complete.

Temporarily disable touch and stylus support for WPF applications

To temporarily disable touch and stylus support, use one of the following methods.

  • Add the following entry to the application configuration to disable touch and stylus support for WPF applications.

        <AppContextSwitchOverrides value=" Switch.System.Windows.Input.Stylus.DisableStylusAndTouchSupport=true"/>
  • Apply the following registry subkey to disable touch and stylus support for WPF applications machine-global.


    Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft can't guarantee that these problems can be solved. Modify the registry at your own risk.

    • Location: HKEY_LOCAL_MACHINE\Software\[Wow6432Node\]Microsoft\.NETFramework\AppContext\Switch.System.Windows.Input.Stylus
    • Name: DisableStylusAndTouchSupport
    • Type: String
    • Value: true


For more information about known issues in the .NET Framework 4.7, see Known issues for .NET Framework 4.7.