A guest downloaded a rom/game and he is finding it difficult it to run at Windows 7 even he has tried to run it under compatibility mode (Windows XP). D3dx9_42.dll errors appear when a game or other software program is started.
Off and on you will find Windows giving error related to missing dll file when you try to start some application or game. What most users do is to search that file name and land at website which will give them dll file to download and use. Well, don’t do that. Websites that allow easy downloads of single DLL files seem like the answer you’ve been looking for when you get one of those annoying “DLL not found” or “DLL is missing” errors. DLL download sites should always be avoided, even though they sometimes provide a quick fix. There are perfectly safe and acceptable ways of fixing DLL problems without resorting to downloading individual DLL files from these sites. Updating your PC drivers, DirectX or software framework can resolve the issue. Usually, the solution to the actual problem is to reinstall the entire software package that the DLL originated from.
There are a number of reasons that you may end up paying more for your easy solution than you might have thought so check out these very important reasons to avoid downloading dll files.
A user pointed me out that he could not start fba emulator to play a game and encountered an error of ‘D3dx9_42.dll Not Found’.
fba.exe does not work, gives error ‘Unable to Locate Component. This application has failed to start because d3dx9_42.dll was not found.‘
Now it looks like that d3dx9_42.dll is missing, but its not. With a fresh installed OS you are most likely to encounter this error / warning. This problem has got an easy solution.
You can increase PC performance by forcing Windows to Unload DLLs from Memory. Windows Explorer caches DLLs (Dynamic-Link Libraries) in memory for a period of time after the application using them has been closed. This can be an inefficient use of memory on low memory systems, and may cause problems or delays for programmers developing with Windows DLL files. Using following method you can force Windows to unload DLLs from memory to free some more system resources.
Open your registry and find the key