If you're experiencing this problem, reinstall DirectX here.
Afterwards, download and install the June 2010 DirectX runtime package. Some older games aren't compatible with the libraries included with current releases of DirectX and this package should help. You can find ZIP file containing its installation files here.
You will have to extract the files into some folder, then open that folder and launch the DXSETUP.exe file in order to proceed with the installation.