First off Im usinf DX 7.1a and the debug DLLs with VC++6. When I call: DDSCAPS2 cp; LPDIRECTDRAWSURFACE7 Primary,BackBuffer; ....//InitPrimarySurface ZeroMemory (&cp, sizeof (cp)); cp.dwCaps=DDSCAPS_BACKBUFFER; Primary->GetAttachedSurface(&cp,&BackBuffer); Whenever I call GetAttachedSurface I get: TEST 3 caused an invalid page fault in module D3DIM700.DLL at 0177:5667d474. Registers: EAX=00000000 CS=0177 EIP=5667d474 EFLGS=00010246 EBX=00550000 SS=017f ESP=0065fcc0 EBP=0065fcd8 ECX=00000000 DS=017f ESI=0065fce4 FS=3d7f EDX=862380a0 ES=017f EDI=862380a0 GS=0000 Bytes at CS:EIP: ff 8f b8 22 00 00 ff b7 b8 22 00 00 8d b7 b8 22 Stack dump: 0065fd34 0065fce4 862380a0 0065fe28 56706024 00000000 0065fd34 0040146a 862380a0 0065fda8 0065fd3c 00550000 cccccccc cccccccc cccccccc cccccccc I have narrowed it down to The GetAttachedSurface seems to have failed also. Why? thanks in Advance, slim

add
cp.dwSize = sizeof(cp);
to your code. That should fix the problem. Remember to always set the dwSize field.

Dethsled

It says:

Dx.cpp(45) : error C2039: ''dwSize'' : is not a member of ''_DDSCAPS2''

What are you trying to do with this?