DLL stands for "Dynamic Link Library". Though there are different explanations given from Microsoft, this one could be the better one:
"A Dynamic Link Library (DLL) is a file of code containing functions that can be called from other executable code (either an application or another DLL). Programmers use DLLs to provide code that they can reuse and to parcel out distinct jobs. Unlike an executable (EXE) file, a DLL cannot be directly run. DLLs must be called from other code that is already executing."
To edit DLL files is not as easy as you think. They are written in many languages, such as C, C++, C#, Delphi, Visual Basic, Visual Basic.Net, and so forth. So you are required a bit of computer professional skills when editing it.
• You attempt to hack it to do something other than what it was intended to do.
• You want to extract Icons from the DLLs.
• You want to reverse engineer an application.
• You are a geek and want to see what it looks like inside.
If you have the reason as above, you can try to edit the DLL file, or you are not supposed to do so. And you'd better ask technicians for help or use professional and easy DLL file editor if you are a computer newbie.
There are different ways to edit DLL files. You can download a DLL editor freeware, or get a DLL resource editor, here I strongly recommend you edit DLL files with a program named "Resource Hacker", which is a free and trustworthy DLL editing tool. You can easily download this program from the Internet.
Launch Visual Studio and go to File > Open. Go to the .dll or .exe file you are trying to open, and before clicking Open.
Now you'll be at a screen that has all of the available resources to you. You can edit the DLL file in the window and then save it.
Note: Once the DLL file is edited and you decide to recover the original file with the new one, there might be some errors when running the program that contains this DLL file. We highly suggest you save the DLL file as a new and think carefully before editing the DLL file.