   What does error D3DERR_NOTAVAILABLE mean?
  I'm trying directx9.But it goes wrong when calling the CreateDevice function and returns an error called D3DERR_NOTAVAIBLE.The book just says 'The Device Do Not Support This Call'.I got really confused.Here is the codes:D3DPRESENT_PARAMETERS D3DPresentParam;ZeroMemory(&D3DPresentParam, sizeof(D3DPresentParam));D3DPresentParam.Windowed = TRUE;D3DPresentParam.SwapEffect = D3DSWAPEFFECT_DISCARD;D3DPresentParam.BackBufferFormat = D3DFMT_UNKNOWN;D3DPresentParam.BackBufferCount = 1;D3DPresentParam.BackBufferHeight = 480;D3DPresentParam.BackBufferWidth = 640;D3DPresentParam.hDeviceWindow = hWnd;HRESULT hResult;if (D3D_OK!=(hResult = lpD3D->CreateDevice(D3DADAPTER_DEFAULT,D3DDEVTYPE_REF,   hWnd,   D3DCREATE_SOFTWARE_VERTEXPROCESSING,   &D3DPresentParam,   &lpD3DDevice))){ return false;}
  Hehe, it means that the host hardware does not support the functionality you are requesting from Direct3D. In other words, you graphics card doesn’t support what ever your trying to do and Direct3D is complaining about it.   ;  Thank you.I have searched the old posts and got the answer.Then one more question. What are HAL and REF.   ;  You have the DirectX SDK, don't you have the documentation that comes with it?If not, I suggest you get it. It is undeniably helpful.Quote:From the DirectX SDK (February 2005)Device Types --------------------------------------------------------------------------------HAL DeviceThe primary device type is the hardware abstraction layer (HAL) device, which supports hardware accelerated rasterization and both hardware and software vertex processing. If the computer on which your application is running is equipped with a display adapter that supports Microsoft Direct3D, your application should use it for 3-D operations. Direct3D HAL devices implement all or part of the transformation, lighting, and rasterizing modules in hardware.Applications do not access graphics adapters directly. They call Direct3D functions and methods. Direct3D accesses the hardware through the HAL. If the computer that your application is running on supports the HAL, it will gain the best performance by using a HAL device. To create a HAL device, call IDirect3D9::CreateDevice using D3DDEVTYPE_HAL as the device type.Reference DeviceDirect3D supports an additional device type called a reference device or reference rasterizer. Unlike a software device, the reference rasterizer supports every Direct3D feature. Because these features are implemented for accuracy rather than speed and are implemented in software, the results are not very fast. The reference rasterizer does make use of special CPU instructions whenever it can, but it is not intended for retail applications. Use the reference rasterizer only for feature testing or demonstration purposes. To create a reference device, call IDirect3D9::CreateDevice method using D3DDEVTYPE_REF as the device type.;  Thank you, I got it.I do not have the documentation. My SDK only have folders of Lib and Include.   