>>Make sure you are using the header file from the SDK, and not from your compiler.<<

Good idea - it's quicker to test and might just work (wish I'd suggested that ). However, I've found that ms headers are not always compatible with mingw and taking this approach might be more troublesome in the long term.

>>2 "NTSecPkg.h" in sdk\include<<

I think that'll be the one that bithub is referring to.

>>if i change to msvc<<

If that's an option for you then that would seem to be an easier route than fighting it out with dev-cpp (mingw).