Corflags is good for checking .exe, and soon, you will realize that it is not effective on checking dll files. Especially for unmanaged dll, you will see this error message
corflags : error CF008 : The specified file does not have a valid managed header
A better way is to use dumpbin with /headers options.
1. Go to start menu, find your VS2010 application folder
2. In Visual Studio Tools, click on Visual Studio Command Prompt (2010)
3. A command prompt environment will be load.
4. Navigate to your assembly location. Type, dumpbin /headers your_assembly.dll. It will display the following for x86 dll and x64 dll respectively. See the highlighted areas