var m_FilterGraph = (IFilterGraph2)new FilterGraph(); int hr = m_FilterGraph.AddSourceFilter(file, "Ds.NET FileFilter", out capFilter); When my project is x64 it will throw System.Runtime.InteropServices.COMException (0x80040241): The source filter for this file could not be loaded. With x86 everything is OK. It's c# code but the problem is present in every x64 app [...] read more