Software

About Windows DLL Files


Dynamic link libraries are files that contain data, code, or resources needed for the running of applications. These are files that are created by the windows ecosystem and can be shared between two or more applications. 

When a program or software runs on Windows, much of how the application works depends on the DLL files of the program.  For instance, if a particular application had several modules, then how each module interacts with each other is determined by the Windows DLL files

One of the main drawbacks of Windows DLL files is the issue of dependency on the programs. If a particular DLL file is accessed by a program and some changes are made to its content, then when another application gets to access the same DLL file and overwrites the data, the first program could then not run on the system.

Dependency issues have been taken note of, and one of the features of the later day Windows operating system and the networking protocols is that the issue is kept to a bare minimum. The use of the Microsoft.NET framework has meant that dependency factors are almost negligible.

How Does a Windows DLL File Help

There are a number of ways dynamic link libraries can help in the smoother running of the computers of the present day. Some are extensions of the past performances, whereas others have been introduced with better networking protocols having taken over the running of the systems.  They can be elucidated as follows.

  1. Modularization of code: Increasingly, when writing codes for long or large programs, it is the practice to modularize it by using sub-routines as far as possible. The use of the Windows DLL system would mean that it is increasingly possible to modularize the coding to a more considerable extent than possible earlier. One of the present issues with trying to do modular has been the concerns when debugging a written program is taken up. The Windows DLL system tends to bring greater flexibility in rendering modular structure and hence helps with the better handling of the files in the system.
  2. Code reuse: It is not strange to find DLL files being shared by two or more applications. Thus it becomes possible to share code between programs and hence reduces the need to re-write code time and again.  The dynamic link libraries have made it possible to share code, data, and resources between two or more applications; thus, it increases the efficiency of the working system by removing duplications.
  3. Better memory use: When an application is run, it calls to action many files all at the same time.  Each time a file, be it a data file or a system file, is called into action, it gets loaded onto the RAM.  This, in turn, overburdens the memory of the computer system.  With the DLL system, it becomes possible to share files between two or more applications. Thus if a particular file is called to action by a program, it can still be used while in the memory by another application as well. This would mean less memory being utilized each time different applications that need to access the same DLL files are chosen.
  4. Less disk space: In case it is possible to share files as the DLL architecture would allow, then it would mean lesser space to store the files. It has to do with the lesser number of files that are needed to be stored in the system to make it function.  Considering the size of the Windows operating system, this saving of space is not such a minor affair and should be taken note. 

Advantages of Using DLL Files

When something as advanced as the dynamic link libraries are used in the operating system, there is bound to be a lot of advantages and positive side to it.  It would only be proper to discuss the most relevant of them, as has been done below.

1. Uses much lesser resources

In case numerous applications call up the same DLL file at the same time or utilize the same Windows DLL file while functioning, then it would mean lesser disk space used up as with the memory as well. When duplication is prevented, it would naturally follow that the system needs to deploy lesser resources to support the working system. Here it would mean an improved performance of not just the application alone but the whole Windows operating system as a whole.

2. Improves modularity of the system

One of the features of modern-day coding is the increasing use of modular systems.  This could translate to a more significant number of subroutines or subordinate programs that support the main application. With the use of the dynamic link libraries, it is possible to take it to the next level of modularity. Since more than a single application can access the data or resources in a Windows DLL files, it would mean that much lesser files to support by the system.

3. Ease of use and deployment

One of the features of the windows system is the constant updates that are implemented to take care of the future requirements of computing. With the DLL files, it is possible to update a single file that is used across different applications to make the entire system up to date. This feature is mainly in use when third party DLL files are used that would mean lesser files to keep updated all the time.

Keeping the dependencies of DLL files in mind

By being dependent on a DLL file, it means that the functioning of the particular program of application is conditional to accessing the said DLL file each time it is required to do so. There are certain instances when this dependency can be harmful to the working of the system, and they have been listed out in the below.

1. Upgradation to a new version

When a dynamic link library file has been called to action, and the file is then updated or upgraded, the application using the program might not be able to interact with the file as before.  It is as though a direct link has been lost to the system at a crucial juncture. 

2. The DLL is fixed

This action usually happens with a DLL file that has been depended on by another application.  When the application is being run, and the file is acting as a dependent one, changing its attribute does change how the system works. Often a quick solution in case this problem is encountered is to restart the computer.

3. The DLL is overwritten

It must be understood that DLL files are just like any other supportive files in the system.  They tend to get upgraded and updated, as well. The trouble occurs when a particular DLL file is overwritten while it is being called to action by an application. It typically occurs when two or more applications access the same dynamic link file, and a running program then overwrites the file.

4. The DLL file is removed

When a dependent DLL file is removed from the working system, it tends to compromise on the working of the application that has called to action the particular dynamic link library file. Here is why often the program hangs or crashes. The typical Microsoft crash report does give a log of the failure, and rectification action is initiated in the right earnest.

The above four issues are generally termed as dependency conflicts. Over the years, as more applications got to using dynamic link libraries, the developers of the Windows operating system have taken steps to control the issue to a large extent. Unless backward compatibility to a program is not introduced, it would not be possible for the system to act as a functioning whole.

Windows protection

Here the system looks for a valid signature before a DLL file is changed in its composition. It prevents the change of the file by third-party applications and software most of the time. This does go a long way in enforcing a great deal of protection to the said files and, thus, a much stable system as a whole.

 As the use and application of the DLL files increases, the steps taken to make them robust and more reliable must be made a note here.

 Private DLLs

 Most DLL files are to be used with more than a single application.  When it is so desired, it is possible to have a private DLL installed in the system. The feature of the private dynamic link libraries is that they can only be accessed by a single application or a group of applications that are restricted in nature. It helps to control the corruption encountered in the use of the DLL files to a large extent possible.

Troubleshooting DLLs

When a computer encounters a DLL dependency problem or any other issues involving the Windows DLL files, it is possible to debug the system using several readily available tools. What the tools do is to run through the relevant files and enact a repair action that would render the files usable once again on the system. 

 Dependency Walker

 This is a repair tool that seeks to restore the corrupt DLL files to their original composition. It seeks out missing DLLs, DLLs that have been changed, and in short, any serious issue concerning the use of the dynamic link libraries.  It is possible to detect and document all the DLL files that are relevant to a program and create a log of it.  Thus the corruption and damage to the DLL are prevented for the particular application.

Universal Problem Solver

 The windows operating system uses the universal problem solver to take care of serious issues that might come out of a corrupt or dependent DLL file. With the Problem Solver, it comprises of three or four components that take care of each part of the dependency crisis. The function of the Dependency Walker file and the Universal Problem Solver are complementary to each other and do not create an overlap.

Finding the running DLL files

One of the features of the DLL files is that they are not very graphic user-friendly. Thus the best method to get to interact with them is using the command prompt or the DOS shell. To know which of the DLL files that are running at a particular time, the command prompt screen is brought up, and the following command executed.  <<tasklist/m>> Type enter and a list of applications running on the system is displayed along with the tree route to the file.

It is possible to open out the DLL file. But most of the time, what is displayed would be machine code or something similar to the viewer. The most advisable thing to do is never to alter any feature or entry in the DLL files and to allow applications that are custom built to handle the issue arising out of the libraries.  

What happens when a Windows DLL file is corrupt?

As has been discussed earlier, the windows operating system itself does have inbuilt troubleshooting and repair programs in the system.  Moreover, some websites are supported by Microsoft that take up the task of further troubleshooting the system and recommend corrective action. Issues of a corrupt file or a deleted DLL file can be fixed in this manner most of the time.

With the later version of networking protocols and the operating systems, it has become increasingly tough to damage a Windows DLL file.  This has to do with the greater dependency of the files than ever before, and Microsoft has taken it upon themselves to deliver a better operating system with few chances of a crash or a program hang. 

Over the years, the dynamic link libraries have been an increasingly important component of the Windows operating system. As with any type of file, it’s quite possible they can be damged, or become corrupted. There are tools within the operating system that can rectify damages and make repairs.


Maggie is a lifelong geek. She loves sharing tips and tricks about new technology and enjoys everything related to computers. Also an avid bookworm and you can always find her, in her favorite laboratory tinkering with computers, smartphones and other devices.