Plz help... texture memory problems!!!

How can I tell if current device uses video or system memory for the textures and if I can use both with that device? Im trying to load textures into system memory if device runs out of video memory. So far I failed miserably. Here is slice of the code I use for surface creation: 1) Create texture surface A in system memory using following caps: DDSCAPS_TEXTURE | DDSCAPS_SYSTEMMEMORY 2) copy image there 3) Create texture surface B using following caps: DDSCAPS_TEXTURE |DDSCAPS_ALLOCONLOAD 4) call Load () function to load image A into texture B If I try to set caps for surface B to :DDSCAPS_TEXTURE | DDSCAPS_ALLOCONLOAD|DDSCAPS_SYSTEMMEMORY or DDSCAPS_VIDEOMEMORY thus explicitly specifying type of memory I want to use, it fails. Any help greatly appreciated. Andrei