The problem with the IID_s is solved ! File-Structure: ~~~~~~~~~~~~~~~ DirectDraw.pas = DDraw.h + DVP.h (+ MultiMon.h) Direct3D.pas = D3D.h + D3DTypes.h + D3DCaps.h + D3DVec.inl + DXFile.h Direct3DRM.pas = D3DRM.h + D3DRMDef.h + D3DRMObj.h + D3DRMWin.h + RMXFGUID.h + RMXFTmpl.h DirectInput.pas = DInput.h (+ DinputD.h) DirectPlay.pas = DPlay.h + DPLobby.h DirectSound.pas = DSound.h DirectMusic.pas = DLS1.h + DLS2.h + DMDLS.h + DMError.h + DMKSCtrl.h + DMusicC.h + DMusicF.h + DMusicI.h + DMusBuff.h DirectSetup.pas = DSetup.h No Unit = dxsdk.inc