If you want all types (including private types) use Assembly.GetTypes()
assembly = Assembly.LoadFrom(@"C:\Users\c_desaik\Desktop\PowerTool.exe");
foreach(Type type in assembly.GetTypes())
Console.WriteLine(type.ToString());
If you want only public types use GetExportedTypes
:
foreach(Type type in assembly.GetExportedTypes())
Console.WriteLine(type.ToString());