The d3d9d.dll file comes from DirectX Video by Microsoft Corporation. DirectX Video allows video acceleration. It is used for both Microsoft Windows and Xbox 360.
The DLL is like a giant filing cabinet. Like all filing cabinets, the DLL files get messed up. The only way to stop registry errors is by regularly cleaning your registry. This can easily be done with a high quality registry cleaner. Not all registry cleaners are alike. ZookaWare PC Cleaner is the only one with a 100% removal guarantee.
ZookaWare PC Cleaner resolves the d3d9d.dll error along with all other registry errors. The 60-day money-back guarantee allows you to remove the registry errors worry free.