How do I decompile a .dll file?

dll decompiler
curiousgeorge picture curiousgeorge · Mar 4, 2011 · Viewed 80.9k times · Source

I have a .dll I would like to decompile to make some improvements to the code. What are some tools out there that will allow me to do this?

It's written in VB, I believe.

Answer

Jonathan Wood picture Jonathan Wood · Mar 4, 2011

The answer depends on what language the DLL was written in.

If it was a .NET language then, as pointed out, you can use .NET Reflector.

If it's the older Visual Basic (pre-.NET), then the DLL is compiled as what's called p-code and there are a few options for doing some variations on decompiling.

Finally, if it's written in a language like C++, there is no direct way to obtain the source code. Such a DLL is compiled to machine language and can only be directly decompiled to assembly language.

So, again, it depends on the language used. And the answer might be that it's just not possible to get anything resembling the original source code.

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