The structure layouts differ among the various strains of Windows, and there also are differences between retail and debug builds of a given version. Many internal structures are documented in the DDKs (device driver development kits), some of which can be downloaded for free from Microsoft''s web site. You might want to look at the ''Undocumented $FOO'' books by Andrew Shulman and Matt Pietrek, who did a good job of dissecting Windows (95) internals and describing the inner workings - including WND and DC layouts. The books have gathered a bit of dust over the years but they give you lots of inside info. A similar resource is the Undocumented Corner in DDJ.

What are you trying to do - reinvent WinG?

read through windef.h in your compiler''s source include directory. all those are described by "DECLARE_HANDLE". This is a macro in (for me) winnt.h:

  #ifdef STRICTtypedef void *HANDLE;#define DECLARE_HANDLE(name) struct name##__ { int unused; }; typedef struct name##__ *name#elsetypedef PVOID HANDLE;#define DECLARE_HANDLE(name) typedef HANDLE name#endiftypedef HANDLE *PHANDLE;