   using DDraw7 headers but with ddraw.dll, work with DX 5+?
  I'm including ddraw.h without defining the DDraw version (I have DX7 SDK so it defaults to DDraw 7 header) and I'm not using things like LPDIRECTDRAWSURFACE7, instead I use LPDIRECTDRAWSURFACE. So will the rendering in theory still work with DX 5 even if you use the DDraw7 header because the ddraw.dll is dynamically loaded?Or do I have to use the DDraw 5 header?Thanks.   
  It should be fine. Why on earth are you use DD5 though? It's about 14 years old...   ;  Thanks. For compatibility with older machines without updated drivers.D3D7 is used with newer machines...   ;  Is it really worth it? DX5 was availiable on Windows 98 and NT 4.0, and later versions are availiable on Windows Update.Do you really want to support operating systems that old without an Internet connection?   