DirectX 9.0 Release Notes
The following sections contain update information for DirectX 9.0 and focus on those areas of the DDI that have been modified or extended for DirectX 9.0:
Note that the DirectX 9.0 runtime only supplies hardware acceleration in any form if the display driver is a DirectX 7.0 or later driver (that is, the driver supports at least the DirectX 7.0 DDI).
The Updates for Windows DDK section contains update information for specific versions of the Microsoft Windows Driver Development Kit (DDK) with which the DirectX 9.0 DDK is installed.
The Updates for Earlier DirectX DDK Versions section contains update information that applies to version 9.0 as well as to prior versions.