A DLL is not meant to be read per se; DLL stands for Dynamic Link Library, and contains collections of functions, shared code and resources (small bitmap images, for example, are stored for all programs to access in Windows' shell32.dll, resident in the OS system directory). Many DLLs also contain predefined methods of communicating and interfacing with the Operating System, which makes it more efficient from a coding standpoint to separate these (possibly large) chunks of code off into their own small container file, and then address the DLL file whenever that functionality is needed. This does mean, however, that applications can develop 'dependencies' on files, meaning they must always be there in a location the program can see, so that it will function properly - this is also why programs can stop working properly or altogether if DLL files become corrupted, are modified or are deleted... And that's also why Microsoft comes with a small utility called, simply, "sfc" (System File Checker), which will go through all the Windows DLLs and other system files, checking for corruption and prompting for replacement or restoration if it finds problematic files. I love to hate DLLs, they're the scourge of my computing life and have been since Windows 95 (though at least VxDs, or Virtual device Drivers / Virtual eXtended Drivers, have been eliminated from the computing landscape, those caused me no end of problems throughout Windows 95 and Windows 98's lifespan, and someone asked me a question about a problem involving VxDs on Windows 98 just yesterday too, so unfortunately these problems refuse to go away and leave us in peace!). That said, DLLs, if compiled correctly, are a useful source of shared code and other resources across applications. Lose the wrong one though, and, to form a rough analogy, it's like losing half of your limbs - more often than not it'll render your computer incapacitated until you perform surgery to repair the damage.

Do you have the source code??? If not, such editing is not for the faint of heart. If you do have the source code and a copy of the development environment the DLL was written in (Delphi, Watcom C, or whatever), AND you know what you are doing, you would 1. make your changes, 2. Compile and link if necessary, then 3. check for satisfying whatever dependencies there are. After that, 4. you need to make sure that you have provided properly formatted inputs and outputs for the other programs that depend on this DLL. Sound complicated? It is bewildering if your not sure what you're doing. I'd advise against it if you are not a programmer.

use the software reshack.exe "google" it, freeware

I think what you are asking for is a Hexadecimal Editor. . www.versiontracker.com/dyn/moreinfo/win/155463 is one written in Java (?!). .

DLL is Dynamic Link Library, files are compiled files. To edit them without the source code, you will need to perform something called "reverse engineering" for which you'll need SDKs (software development kits), IDE's (Integrated Development Environment) and other software tools. You'll also have to be able to read and understand cryptic code. This is not something you can do with just notepad. Also, there may be legal issues involved with reverse engineering (in that it may be strictly forbidden by the license agreement for whatever it is you are attempting to decompile). Modifying a DLL can render the program that uses it completely unusable. If this is a system DLL used by Windows, it can render your system useless (usually until said DLL is replaced with a non-corrupt version).