The file d3df.dll is a 3DA Direct3D Wrapper made by ToMMTi-Systems. Wrappers are programs that work as mini-emulators, allowing a user to run software meant for certain types of hardware on a computer that does not have that hardware. In this case, the wrapper allows users to run Direct3D programs on a computer that does not have a 3D video card.
If you are seeing an error with this file, the Direct3D wrapper will not work and you will not be able to run the games that need the wrapper. You should try cleaning your registry to solve this problem.
The registry tracks the files on your machine, letting Windows know where each file lives and how to use it. If the registry has a mistake in it, Windows can’t find the file and your programs will not run.
Use ZookaWare PC Cleaner to clean up registry mistakes. ZookaWare PC Cleaner will solve the problems for you so you can get back into the game instead of fussing around with the registry. Run a free ZookaWare PC Cleaner scan to find out if ZookaWare PC Cleaner can help you.