A .NET based application installer that I have here fails to initialize. This happens during WPF initialization because it fails to load C:\windows\Microsoft.NET\Framework64\v4.0.30319\WPF\PresentationFrameWork.light.dll. An investigation shows that the installer (or rather WPF) uses uxtheme.GetCurrentThemeName() to build the target DLL name for loading. Under Windows 10/11 directory C:\WINDOWS\Microsoft.NET\Framework64\v4.0.30319\WPF doesn't contain PresentationFrameWork.light.dll neither, it has the following backends for the theme support: PresentationFramework.Aero.dll PresentationFramework.Aero2.dll PresentationFramework.AeroLight.dll PresentationFramework.Classic.dll PresentationFramework.Luna.dll PresentationFramework.Royale.dll and C:\WINDOWS\Resources\Themes contains only 2 files with extension .msstyles: aero\aero.msstyles and aero\aerolight.msstyles. Further experiments with installing and switching between different themes under Windows shows that regardless of current active theme the call uxtheme.GetCurrentThemeName() always returns "C:\WINDOWS\resources\themes\Aero\Aero.msstyles". -- v2: uxtheme/tests: Add a test to show that current theme name is supposed to be "aero.msstyles". dlls: Rename light.msstyles to aero.msstyles. https://gitlab.winehq.org/wine/wine/-/merge_requests/10042