Gac.cs

public static class Gac
{
    /// <summary>
    /// 
    /// </summary>
    /// <param name="pattern">Default search pattern  "*interop*.dll"</param>
    /// <returns></returns>
    public static IEnumerable<FileInfo> InteropDlls(string pattern = "*interop*.dll")
    {
        var gac = AllFiles(new DirectoryInfo(@"C:\Windows\Assembly"), pattern)
                                                .OrderBy(x => x.Name)
                                                .AsEnumerable();
        return gac;
    }
    public static IEnumerable<Assembly> InteropAssemblies(string pattern = "*interop*.dll")
    {
        var dlls = InteropDlls(pattern);
        var assemblies = new List<Assembly>();
        foreach (var fileInfo in dlls)
        {
            try
            {
                Assembly assembly = Assembly.LoadFile(fileInfo.FullName);
                assemblies.Add(assembly);
            }
            catch (Exception e)
            {
                Debug.WriteLine("Error loading assembly {0} {1}",fileInfo.FullName, e.Message);
            }
        }
        return assemblies;
    }
    private static IEnumerable<FileInfo> AllFiles(DirectoryInfo dir, string searchPattern, IList<FileInfo> files = null)
    {
        if (files == null)
            files = new List<FileInfo>();
        try
        {
            foreach (FileInfo f in dir.GetFiles(searchPattern))
            {
                files.Add(f);
            }
        }
        catch(Exception e)
        {
            Debug.WriteLine("Error reading directory {0} {1}",dir.FullName, e.Message);
            return files; 
        }
        foreach (DirectoryInfo d in dir.GetDirectories())
        {
            AllFiles(d, searchPattern, files);
        }
        return files;
    }
}