What is dll?\r\nWhat is dll? The dll is an abbreviation of the term Dynamic Link Library, but still for you this term isn\u2019t an answer for the question of \u201cwhat is dll\u201d, so I will describe briefly and will make it clearer below.\r\nTo have an idea of what is dll, you have to understand that a DLL also a library that contains code and data which can be used by more than one program at the same time, hence, a DLL controlling and facilitating the operations for any Microsoft Windows based program, and for an example there are programs which may contain many different modules and each of those modules of the same program contained and distributed via DLLs.\r\nGenerally, DLLs are represented by files with the extension of \u201c.dll\u201d at the end of the file name, but some DLL files are used in several different file extensions as the DLL functionality located within its code.\r\nWhat is DLL advantage\r\nUnderstanding what is dll from above isn't enough to get the full picture of it, there are many benefits and advantages behind using the DLLs in programs or within Microsoft Operating Systems\u00a0which makes you realize more what is dll:\r\n\r\nDLL helps promote modularization of code. (Each module of a code uses a DLL to function).\r\nDLL helps code reuse.\r\nDLL helps making efficient usage of the memory. (By using fewer resources as many programs may use the same DLLs).\r\nDLL reduces disk space.\r\nDLL makes the Operating System load and run faster.\r\nDLL make programs load and run faster.\r\nUpdating programs are easier using DLLs.\r\n\r\n Note:\u00a0Program updates are easier to apply to each module without affecting other parts of the program; hence you can apply an update without needing to install the whole program again. \r\nWhat is DLL risk\r\nThe risk behind DLLs is all about being used by malicious software or virus which is called DLL Hijacking, this happened by a malicious code injected into an application via a malicious DLL with the same name as a DLL used by the application, and that\u2019s why Windows File Protection implemented (you will read about it below).\r\nOne of the solution to solve such issues by running an updated antivirus software in safe mode and scan for viruses.\r\n Note:\u00a0Correct deep steps on how to clean you Windows from viruses from my other article\u00a0How to clean my PC from Viruses?. \r\nWhat is DLL problem\r\nTo have a full understanding of what is dll, you need to understand the dll problems and solutions, many programs issues cause by the DLLs, and especially for those programs or tools that do not run when you try to execute them while getting an error message of a corrupted or missing dll files, and off course this caused by an issue called dependency.\r\nI will simplify it more, when a program uses a DLL, a dependency is created, if another program overwrites and\/or breaks this dependency, the original program may not successfully run and you will get the error message or dialogue box, these actions are known as DLL conflicts.\r\n\r\n \r\n\u00a0i.e.: If one of the following actions occurs:\r\n \r\n\r\nA dependent DLL is upgraded to a new version.\r\nA dependent DLL is fixed.\r\nA dependent DLL is overwritten with an earlier version.\r\nA dependent DLL is removed from the computer.\r\n\r\n\u00a0any program may not run\r\n \r\nHow to deal with DLLs problems or issues and DLL troubleshooting?\r\nNow, I can categorize the answer for this question into two categories, the prevention and protection, and the second is manual troubleshooting.\r\nDLL issues Prevention and Protection:\r\nMicrosoft has made a protection for DLLs in their Operating Systems to minimize the dependency issues in two ways:\r\n\r\nWindows File Protection: The Microsoft Operating System is preventing DLLs from being updated or deleted by any unauthorized third parity agent, hence when DLL modification requested by a third parity program (i.e. software installation), Windows File Protection will look for a valid digital signature to allow the installation process.\r\nPrivate DLLs: By using the Private DLLs, the program will be isolated from changes that are made to shared DLLs. Private DLLs use version-specific information to enforce the version of the DLL that is used by the program in the program root folder\r\n\r\nDLL issues manual troubleshooting:\r\nThere are a couple of tools that you may use to solve and troubleshoot DLL issues:\r\n1. Dependency Walker: A tool where you use to open your defected program and check its DLLs for:\r\n\r\nMissing DLLs.\r\nProgram files or DLLs that are not valid.\r\nImport functions and export functions match.\r\nDLLs Circular dependency errors.\r\nModules that are not valid for a different operating system.\r\n\r\n Note:Using Dependency Walker tool, you can document all the DLLs that a program uses. This may help prevent and correct DLL problems that may occur in the future. \r\nTo download Dependency Walker tool and read more about how to use it from the below button:\r\nDependency Walker Download\r\nDependency Walker Download\r\n2. DLL Universal Problem Solver DUPS:\u00a0The DLL Universal Problem Solver (DUPS) tool used to compare,\u00a0audit,\u00a0document, and display DLL information such as the below utilities that DUPS tool uses:\r\n\r\nDlister.exe:\u00a0This utility enumerates all the DLLs on the computer and logs the information to a single text file or a database file.\r\nDcomp.exe:\u00a0This utility compares the DLLs that are listed in two text files and produces a third one that display the differences.\r\nDtxt2DB.exe:\u00a0This utility loads the text files that are created by using the Dlister.exe utility and the Dcomp.exe utility into the dllHell database.\r\nDlgDtxt2DB.exe:\u00a0This utility provides (GUI)\u00a0a graphical user interface of Dtxt2DB.exe.\r\n\r\nTo download and learn how to use the DLL Universal Problem Solver (DUPS) tool from Microsoft via the below button:\r\nDLL Universal Problem Solver (DUPS) Download\r\n If you find this article useful please share it from the facebook button below or other social buttons. \r\nHope you had an answer for your question of What is dll, don't hesitate to leave a comment below.