How to Install D3dx9

1. Launch your Web browser and navigate to a page where you can download d3dx9_31.dll for free. You can find a link to one of these download locations in the Resources section.
2. Click the download link and follow the on-screen prompts to save the file to your computer.
3. Open the file by double-clicking it. The file will open in Winzip, WinRAR or whichever program our computer uses to open .zip files. When the file opens, click 'Unzip' or 'Extract' to extract the file. When the program asks you where you want to extract the file, select your computer's desktop. D3dx9_31.dll should appear on your desktop.
4. Double-click the 'My Computer' icon, then double-click the 'C:' drive. Navigate through the folders to the Windows system folder. This folder is 'C:\Windows\System32' in Windows XP and Vista for 32-bit systems, 'C:\Windows\SysWOW64' in Windows XP and Vista for 64-bit systems, 'C:\WINNT\System32' in Windows 2000 and NT, and 'C:\Windows\System' in Windows ME, 95 and 98.
5. Find the d3dx9_31.dll file you extracted onto your desktop and drag it into the system folder. You may see a message from Windows asking you if you'd like to replace the existing file with the new one. If you see this, it means that an older version of the file, which may be corrupted, is already in the folder. Click the 'Yes' button to overwrite the old file.
6. Reboot your computer. Windows won't recognize the new file as part of the file system until you reboot.