With the v118 of the d3d9.dll, make sure you're only using the original version of Midhrastic. If you already have a redist installed & try to reinstall, it should (by default) ask if you want to overwrite or repair the existing version of that particular redist. files, not the game directory) to the best of my knowledge, whilst the d3d9.dll from the enb wrapper only be placed in your Fallout3 directory. The C++ redist should only ever be installed into the default location (of your O.S. I am running the oldest (v118) version of the d3d9.dll file. I replaced the older version located in the game folder by default, nothing. The June 2010 directx redist goes in the game folder, right? I also installed it on my C: drive and ran the exe on both. Unfortunately, I have all of my drivers, all of the Windows updates, have tried all of the fixes and still, nothing. The guy on Reddit was in the exact same situation as me. Here's some links that may contain useful info. may require that additional step I mentioned to fix the problem you're experiencing with the d3d9.dll from ENB. Installing the game on a modern machine + O.S. Yes, but bear in mind Fallout3 came out in late 2008.

Doesn't a redist exe come with the Fallout installation by default? If so, I've seen it and installed it.

Nexus mods fallout 3 d3d9.dll