What is a DLL File in Windows?

A file with an extension .DLL contains many small tools. Codes and Procedures make up the ‘Dynamic Link Library’. DLL is its abbreviation. Any Windows Program on your PC can use these tools.

To do one specific task, a program ‘calls’ the related code within a DLL file. You can use this format to share data. Other Resources are shareable as well. So, more than one application can use them.

Only one DLL file is enough for them. Simultaneous access is available to all programs. Use its contents as per your needs.
Like any other tool, DLL files can have problems. Want to solve them? Or do you need a heads-up? Keep on reading.

Reasons for Missing DLL Files

Why missing DLL errors are so common? As you can guess, the most common “missing or not found DLL errors” occur because of missing DLL files. Well, there are many reasons for DLL error, but the main reasons for missing DLL files are as below.

1. Mistakenly deleting a DLL file

This may happen when a program is uninstalled/installed or you have tried to clean up space on the hard disk.

2. Overwriting DLL file

A recent application installation sometimes overwrites an existing DLL file with an incompatible or invalid DLL file.

3. Malware Infection

A malicious program has deleted or damaged a DLL file.

4. DLL file is corrupted or crashed

A bad installation of a program corrupted one or more files causing the .dll errors.

5. Hardware Malfunction

Malfunctioning hardware such as a bad hard disk drive damaged the data on the drive, caused the .dll file error.

One of the common errors which Windows users face is caused due to missing DLL files. What do you do if you receive a .dll file is missing error message? We have already taken a look at what to do if you find the following DLL files missing Now let’s take a look at the general steps you could take if you receive such error messages.DLL stands for Dynamic Link Libraries and are external parts of applications that run on Windows 10/8/7 or any other operating systems. Most applications are not complete in themselves and store code in different files. If there is a need for the code, the related file is loaded into memory and used. If the OS or software is not able to find the concerned DLL file, or if the DLL file is corrupted, you could receive a DLL file is missing message.

A DLL is a library that contains code and data that can be used by more than one program at the same time. For example, in Windows operating systems, the Comdlg32 DLL performs common dialog box related functions. Each program can use the functionality that is contained in this DLL to implement an Open dialog box. It helps promote code reuse and efficient memory usage.

By using a DLL, a program can be modularized into separate components. For example, an accounting program may be sold by module. Each module can be loaded into the main program at run time if that module is installed. Because the modules are separate, the load time of the program is faster. And a module is only loaded when that functionality is requested.

Additionally, updates are easier to apply to each module without affecting other parts of the program. For example, you may have a payroll program, and the tax rates change each year. When these changes are isolated to a DLL, you can apply an update without needing to build or install the whole program again.

The following list describes some of the files that are implemented as DLLs in Windows operating systems:

• ActiveX Controls (.ocx) filesAn example of an ActiveX control is a calendar control that lets you select a date from a calendar.
• Control Panel (.cpl) filesAn example of a .cpl file is an item that is located in Control Panel. Each item is a specialized DLL.
• Device driver (.drv) filesAn example of a device driver is a printer driver that controls the printing to a printer.

DLL advantages

The following list describes some of the advantages that are provided when a program uses a DLL:

• Uses fewer resourcesWhen multiple programs use the same library of functions, a DLL can reduce the duplication of code that is loaded on the disk and in physical memory. It can greatly influence the performance of not just the program that is running in the foreground, but also other programs that are running on the Windows operating system.
• Promotes modular architectureA DLL helps promote developing modular programs. It helps you develop large programs that require multiple language versions or a program that requires modular architecture. An example of a modular program is an accounting program that has many modules that can be dynamically loaded at run time.
• Eases deployment and installationWhen a function within a DLL needs an update or a fix, the deployment and installation of the DLL does not require the program to be relinked with the DLL. Additionally, if multiple programs use the same DLL, the multiple programs will all benefit from the update or the fix. This issue may more frequently occur when you use a third-party DLL that is regularly updated or fixed.

DLL dependencies

When a program or a DLL uses a DLL function in another DLL, a dependency is created. The program is no longer self-contained, and the program may experience problems if the dependency is broken. For example, the program may not run if one of the following actions occurs:

• A dependent DLL is upgraded to a new version.
• A dependent DLL is fixed.
• A dependent DLL is overwritten with an earlier version.
• A dependent DLL is removed from the computer.

These actions are known as DLL conflicts. If backward compatibility is not enforced, the program may not successfully run.

The following list describes the changes that have been introduced in Windows 2000 and in later Windows operating systems to help minimize dependency issues:

• Windows File ProtectionIn Windows File Protection, the operating system prevents system DLLs from being updated or deleted by an unauthorized agent. When a program installation tries to remove or update a DLL that is defined as a system DLL, Windows File Protection will look for a valid digital signature.
• Private DLLsPrivate DLLs let you isolate a program from changes that are made to shared DLLs. Private DLLs use version-specific information or an empty .local file to enforce the version of the DLL that is used by the program. To use private DLLs, locate your DLLs in the program root folder. Then, for new programs, add version-specific information to the DLL. For old programs, use an empty .local file. Each method tells the operating system to use the private DLLs that are located in the program root folder.

DLL troubleshooting tools

Several tools are available to help you troubleshoot DLL problems. The following tools are some of these tools.

Dependency Walker

The Dependency Walker tool can recursively scan for all dependent DLLs that are used by a program. When you open a program in Dependency Walker, Dependency Walker does the following checks:

• Dependency Walker checks for missing DLLs.
• Dependency Walker checks for program files or DLLs that are not valid.
• Dependency Walker checks that import functions and export functions match.
• Dependency Walker checks for circular dependency errors.
• Dependency Walker checks for modules that are not valid because the modules are for a different operating system.

By using Dependency Walker, you can document all the DLLs that a program uses. It may help prevent and correct DLL problems that may occur in the future. Dependency Walker is located in the following directory when you install Visual Studio 6.0:

drive\Program Files\Microsoft Visual Studio\Common\Tools

DLL Universal Problem Solver

The DLL Universal Problem Solver (DUPS) tool is used to audit, compare, document, and display DLL information. The following list describes the utilities that make up the DUPS tool:

• Dlister.exeThis utility enumerates all the DLLs on the computer and logs the information to a text file or to a database file.
• Dcomp.exeThis utility compares the DLLs that are listed in two text files and produces a third text file that contains the differences.
• Dtxt2DB.exeThis utility loads the text files that are created by using the Dlister.exe utility and the Dcomp.exe utility into the dllHell database.
• DlgDtxt2DB.exeThis utility provides a graphical user interface (GUI) version of the Dtxt2DB.exe

Fix Missing DLL files error

If DLL files are missing on your Windows 11/10/8/7 computer, the best ways to fix such errors are as follows:

1. Run the built-in System File Checker tool to replace missing or corrupted operating system files
2. Run the DISM tool and repair the Windows system image and fix a corrupted Windows Component Store
3. Repair or re-install the software if some application throws up this error
4. Download Windows 10 OS files from Microsoft
5. Copy the DLL file from another system and restore it on your PC, followed by re-registering the dll file
6. Download dll files from a 3rd-party site – Is that advisable?

Let us take a look at these in detail.

1] Run System File Checker

The safest way to fix DLL file missing or corrupted errors thrown up by your Windows operating system would be to run the built-in System file checker, which will replace missing or corrupted system files.

To do this, on your Windows 10 computer, right-click on the Start button to open the WinX Menu and click on Command Prompt (Admin) link.

Now in the elevated CMD window, copy-paste the following command and hit Enter:

sfc /scannow

2] Repair System Image

If the issue is resolved, great! Else the next thing to do would be to Run DISM to repair the system image Again, in an elevated command prompt window, copy-paste the following command and hit Enter:

Dism /Online /Cleanup-Image /RestoreHealth

This checks for the Windows component store corruption and restores good health. The scan may take around 15 minutes, and once it completes successfully, you should restart your PC.

3] Re-install the software

If it is some installed software or application that is giving this error, all you need to do is re-install the software. You may uninstall the application that is giving the error from the Control Panel, restart your computer, then go to its official download page and download the latest setup file. Having done this, install the software. The installer will place all the required files on your PC including the DLL files. If the software offers an option to Repair the program, you may first opt to repair the installation and see if that helps.

4] Download Windows OS files from Microsoft

If it is an OS dll file that is giving errors, you can download windows 10 from microsoft This is a safe option.

5] Copy DLL from another healthy system

Sometimes, a software that was meant to run on an older version of Windows, may require a specific version of a DLL file to run. If you face this issue, you should try and copy this DLL file from one of your other systems and replace it here in the proper Directory and see if that works for you. You may have to re register the dll file. At times the developers of that software may offer various versions of DLL files on their sites for download – you could download these.

6] Download DLL files?

Is there any good site from where you can download DLL files to restore them? There may be, but I would not advise using them really. The reason is simple. If you need to replace or restore DLL files, you can carry out any of the above-mentioned suggestions. That will ensure that you get genuine files from genuine sources. Moreover, most of the DLL files are copyright protected, and I am not sure if any dll download website has taken the permissions from the OS or software developers to host and distribute the files. And plus – how would you know the genuinity of the file? So that is a call you will have to take.

Use the power of System Restore

Do you like experimenting with your System? If yes, it is possible that an important file has changed. A System Restore is going to undo the changes. Thus, the DLLs can come back. The errors will stop appearing.

Windows users create a system restore point. It is a copy of the Configuration. To protect the computer, you can save a Copied Configuration. It also notes the time before making changes to your system.

If you create a restore point on a periodic basis, it can be a life saver. This is true for the DLL errors as well. See these steps to use System Restore.

1.  right-click on This PC or My computer
2. go to Properties option
3. now, click System Security > System protection
4. Find the ‘System Restore’ option.

Your screen should look like the following snapshot.

Safe mode is always helpful for any situation. You can use it to start System Restore. Have Windows 10? Don’t worry. We have guides for all versions.
Depending on your operating system, follow these steps.

If you have Windows 8/10/11 in your computer:

1. Click the Restart button. Remember to long-press the Shift key when you do it.
2. You will see ‘Choose an Option’ menu. Find the ‘Troubleshoot’ option.
3. You will see ‘Advanced Options’ in it. Click it.
4. Now, in ‘Startup Settings’ menu, click Restart.
5. For accessing Safe Mode, you should press a key. Any version of Safe Mode is available.
6. By right-clicking Start button, you can choose Command Prompt (Admin).

If you are running Windows 7:

1. You need to press F8 key. And do it when PC is booting up. You can access Advanced Boot Options menu. But you must be fast. If you have SSD, you might need to try more than once.
2. Using the Arrows Keys, select Safe Mode with Command Prompt option. You should see the Command Prompt window (CMD) in some seconds.

When you are in it,

1. type cd restore.
2. then type the command rstrui.exe
3. You will see the System Restore window. See the screengrab below for getting a general idea.

Once you start the System Restore tool, the dialogue box will help you. In a step-by-step manner, you will be able to complete the Restoration. After finishing the process, try to see if missing DLL files error are still present or not.

Run DISM

This solution is almost similar to the first one. We use DISM (Deployment Image & Servicing Management) tool when the SFC Scanner fails to repair system files or find the missing DLL file (that we need in our case). Let us know.

Step 1 – You need to run “Administrative Command Prompt”, by right-clicking on the start button (as shown above).

Step 2 – Now, you need to enter the following command into command the Command Prompt and then press “Enter”:

DISM /Online /Cleanup-Image /RestoreHealth

Step 3 – Once you are done with the above process, you need to wait for a while until the process is completed.

Step 4 – Once the process is completed, restart your computer.

If the SFC Scanner didn’t work for your problem, DISM will surely work for you. But even this DISM tool fails to fix missing DLL, you will have to fix it manually by yourself.

. Scan for the Malwares or Viruses

Internet is a dangerous space. And your browser or a pendrive can harm your machine. DLL errors might exist because of a cyberthreat.

A virus or malicious piece of software can hide as DLL object. Since the applications can suffer, you should perform a thorough Device Scan. Download a well-known authentic antivirus software. So, you can scan all the possible causes of any issues.

As you remove the virus or malware, your DLL issues would be over. Update all the Virus Definitions. And you can avoid system issues in the future.

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