How to Edit DLL Files

by Stephen Lilley

There are multiple reasons why a person would want to edit a file with a .DLL extension. You could be trying to change what the file was originally intended to do, or attempting to repair it if it has become corrupt. You could want to "reverse engineer" the application it is being used by and need to see its contents. Or, you could just be curious and want to see what a .DLL looks like. Whatever the reason, while it does require a little bit of computer experience, editing a .DLL isn't nearly as difficult as one would think.

Consider the reason you are attempting to edit a .DLL file. If it is a .DLL that is filled with icons, there are programs you can download that will do all the work for you. The program "Reflector," for example, has a setting under the "Tools" menu for extracting icons. Load the file into the program and select this option. If this is your intended purpose, obtain one of these shareware programs from the Internet and your job is done (see Resources).

Obtain a .DLL decompiler. If you are editing the .DLL for any other reason than to take the icons out of it, you are going to need a piece of decompiler software. This is a program that will take the .DLL apart and make several different smaller parts out of it. Freeware programs that will work include W32DASM and Reflector (see Resources).

Run the decompiler. Once you start the program and tell it which file you are working with, it will then do its job and separate the file into a few workable parts. You can do this by selecting "Add File" under the "File" menu, and telling it which file you are working with. Then hit the "Decompile" button on the main program window. You can then see the code and make any necessary changes from within the program itself.

Recompile the .DLL. Once you have finished your editing, you can tell the Decompiler software to take all the separate parts of the file it made and put them back together as one. Once the software is loaded into the Decompiler, select "Recompile" from the "File" menu to complete this operation.


  • close Always make a copy of the original file before you set about changing it, just in case anything goes wrong during editing.

About the Author

Stephen Lilley is a freelance writer who hopes to one day make a career writing for film and television. His articles have appeared on a variety of websites. Lilley holds a Bachelor of Arts in film and video production from the University of Toledo in Ohio.

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