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

Consider the following scenario:

• You have a touch device that is running Windows 7 Service Pack 1 (SP1) or Windows Server 2008 R2 SP1.
• Some Windows Presentation Framework (WPF) applications are running on the device.
• You install the May 2017 Preview of Quality Rollup for the .NET Framework 4.6, 4.6.1, and 4.6.2 (KB 4104606) on the device.
• You then install the .NET Framework 4.7 on the device.

In this scenario, the WPF applications fail and generate error messages that resemble the following message:

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 work around this problem, uninstall and then reinstall the .NET Framework 4.7.
 

Uninstall the .NET Framework 4.7

1. In Control Panel, click Uninstall a program in the Programs category.
2. In the list of programs, locate and click Microsoft .NET Framework 4.7, and then click Uninstall/Change.
3. In the .NET Framework 4.7 Maintenance wizard, click Remove.NET Framework 4.7 from this computer, and then click Next.
4. If the following warning window appears, click Continue.
   
   
   
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. Click Check online for updates from Windows Update.
3. After the search for updates is complete, click Optional Updates available.
   
   
   
4. Locate and select Microsoft .NET Framework for Windows 7 and Windows Server 2008 R2, and then click OK.
   
   
   
5. Wait for the installation to complete.

Microsoft is working on a resolution to this problem.

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