WPF MessageBox looks unmanageable and WindowsForms MessageBox looks pretty good

This issue can be fixed by adding the application manifest (Add -> New Item -> File Manifest File)

    ...
</trustInfo>
<dependency>
    <dependentAssembly>
        <assemblyIdentity
            type="win32"
            name="Microsoft.Windows.Common-Controls"
            version="6.0.0.0"
            processorArchitecture="*"
            publicKeyToken="6595b64144ccf1df"
            language="*" />
    </dependentAssembly>
</dependency>

      

        
        
        
      

    

In "Project Properties" specify "Manifest" in the newly created file. This is not necessary so that the manifest can be simply deployed along with the EXE file.

Note. This manifest can be used for any executable, not just WPF, which needs to be "styled".