This file is a part of Microsoft Windows Operatin System. Was developed by MicrosoftCorporation.
This is a system file, or, possibly, hidden. It is usually located in %System% folder and its size is 1 Kb.
What options do you have to get rid of "d3d9.dll fallout 3 download" issue.
In the majority of cases, the solution of d3d9.dll fallout 3 download issue is to correctly reinstall particular software that is using this file on your PC, to the Windows system folder, or to the game or application installation folder.
But in case you do not have the installation distributive of application or just do not know, what program is using this file – you should probably download this missing or damaged file and put it in the right folder.