Open DLL File

Open DLL File

DLL file is an executable file which is used as "Dynamic Link Library" or "Application Extension". Microsoft Windows applications can open DLL file and execute code from it. One DLL file could be shared between multiple Windows application. Also Microsoft Windows OS uses DLL files to store executable code for different windows components (graphical engine, networking, printing, etc.).

DLL is one of the most frequently occuring file extensions on your PC. Most of DLL files are located in C:\Windows\System32 folder. Also Windows applications store DLL files in their corresponding folders in "Program Files" and "Program Files (x86)" folders. When you launch a Windows OS application it will look for its DLL files in the folder where you launch it from and will try to open DLL files and load them into memory.

Open DLL File on Windows

• Run application which uses DLL you want to open
• Use hex eitor like HxD, WinHex, UltraEdit to open DLL file in hex mode
• View DLL dependencies using Dependency Walker tool
• Use text editor like Sublime Text, UltraEdit, Notepad++ to open DLL file in text mode
• Disassemble DLL file using Microsoft Disassembler DUMPBIN.exe tool and review output

How to Open DLL File

If you want to check if a specific file is a DLL you can do it via following methods:

• Open DLL file with text editor or a hex editor. Check if the first two symbols in the file are MZ and the rest are binary symbols. If it is so and extension of the file is DLL then most probably it is a real DLL file.

Below is an example of DLL file opened in Dependency Walker in Windows OS.

Please note that DLL files could contain dangerous viruses that can do serious damage to your computer. Do not download DLL files from the internet and do not replace your local DLL files with ones which origin is questionable.

Applications which can open DLL files

• Microsoft Visual Studio. Visual Studio is capable of opening DLL file and viewing and editing certain sections of it like textual resources, icons, messages, etc.
• Microsoft Disassembler. It is part of visual studio but it will allow you to view DLL file in great details. It will decompile DLL from binary code to assembly instructions which are much easier to read than binary code.

Similar file extensions

• EXE files - executable code for applications
• SYS files - executable OS code
• COM files - old DOS style format for executable code
• DRV files - executable code for drivers
• SCR files - executable code for screen savers