How do you fix missing dll files on Windows 11?

A couple of years ago I purchased and downloaded some software from NIST in USA called REFPROP.  This is an industry standard used by chemical engineers and by other software for substance properties prediction.
I wanted to use the software via a dll call from Excel.  The software was written as 32 bit and the installation software therefore put it in the Program Files (x86) folder.  The only way around this - so far - was to copy over the relevant DLL files into the Program Files folder.
When starting Excel it automatically looks in the x86 folder and so I go to Options>Add-ins>Go> then Browse (as Roaming sends it to the X86 folder) to Windows(C:)>Program files>REFPROP> and click the Excel Add-in. and click OK. 

I get a message that it cannot find the ...xla it in the x86 folder - which I ignore and accept deletion from the list.
I can then open my Excel files (of which I have a lot) and the links to REFPROP work just fine.
This is a slightly tedious solution, but it works OK.
If there is a more elegant approach I would be interested to try.

Sure thing! In my experience, when you run into those annoying "DLL file missing" errors, a tool like Dll Fixer can be a real lifesaver. It automates the tedious process of finding and fixing DLL files. Just run a scan, and usually, it'll patch things up pretty quickly.

I followed this tutorial (worked greatly)

https://www.reddiite.com/fix-dll-issues-on-windows

Definitely worth a try!

You can try downloading the missing DLL file from a trusted source and place it in System32 or SysWOW64.  

If you're tempted to start replacing system DLLs (like those in the System32 or SysWOW64 folders), create a system restore point first! That way, if something goes horribly wrong, you can roll back your system to a working state. I learned this the hard way after rendering my OS unbootable and spending half a day reinstalling Windows. 

Don't just Google and grab any DLL to fix corrupted DLL files, this is a HUGE no-no. There are tons of shady websites out there hosting DLL files. Downloading from them is a recipe for malware, viruses, or incompatible files that'll mess up your system even more. I've seen it happen where people download a DLL, and suddenly their computer is riddled with pop-up ads or worse.

Before we dive into more complex fixes, let's make sure your Windows 11 is up-to-date. Microsoft often releases updates that include DLL fixes or patches, so this could resolve your issue. Head to Settings > Update & Security > Windows Update and click on 'Check for updates'.

About how to fix missing DLL files on Windows 11, you can use the DlSM (Deployment Image Servicing and Management) Tool
The DlSM tool is another powerful utility that can help fix issues related to system files, including DLLs. To use it:

1. Open Command Prompt as an administrator (same steps as above).
2. Type dlsm /online /cleanup-image /restorehealth and press Enter.
3. DlSM will scan your system files and repair any issues it finds.

Manually downloading and replacing DLL files is a method I used when I encountered the problem of fix corrupted dll files. Although it is a bit cumbersome, it can be effective if all other methods have failed.

1. Identify the missing DLL file: Usually the program will indicate which DLL file is missing. For example, you will see an error message saying "missing xxx.dll". Note the file name.
2. Download the DLL file: I went to some trusted DLL download sites (such as DLL-files.com) to download the missing DLL file. Be careful to choose the download source here to ensure that the file is safe and avoid downloading viruses or malware.
3. Replace the DLL file: After downloading, I copied the DLL file to the correct location, usually C:\Windows\System32 folder, or C:\Windows\SysWow64 folder if it is a 64-bit system.

This manual method can help you fix corrupted dll files, especially if the system files are corrupted or the program is not installed completely. However, manually downloading and replacing DLL files is risky, so be sure to download the file from a reliable source. Overall, this is an effective solution.

Running the D1SM (Deployment Imaging Service and Management Tool) is an effective way to fix corrupted system files, including DLL files, on Windows 11. D1SM repairs the Windows system image, which can fix corrupted dll files on Windows 10/11 underlying issues causing DLL corruption. 

Step 1: Press Win + S, type cmd, right-click on Command Prompt, and select Run as administrator.

Step 2: Check the health of your system image. This command quickly checks for corruption but does not make any changes.

D1SM /Online /Cleanup-Image /ScanHealth

Step 3: If the health check indicates issues, run a more detailed scan. It scans the system image for corruption and reports any issues.

Step 4: If corruption is found, repair the system image with the following command as it downloads and replaces corrupted files from Windows Update or a specified source.

D1SM /Online /Cleanup-Image /RestoreHealth

The repair process may take some time (10–30 minutes or more, depending on your system and the extent of corruption). Do not interrupt the process. Once the process is complete, restart your computer.

Additional Notes:

1. If the corrupted DLL is associated with a specific program (not a system file), reinstalling the program may be necessary.

2. Always ensure your system is up to date by running Windows Update (Settings > Windows Update).

I've found that many times the missing DLL files are actually a result of a program not being fully installed during installation, resulting in missing files. I tried this method:

Uninstall the problem program: Simply uninstall the program that says it's missing DLL files from Settings > Apps.

Reinstall: Then re-download and install the program from the official website or a reliable source. After reinstalling, the program will usually automatically repair any missing DLL files and the problem will be solved.

This method is particularly effective for situations where the DLL files of a specific program are missing.

I have encountered the problem of missing dll file on Windows 11 before. I tried many methods and finally solved it by running the System File Checker (SFC). In fact, this method is quite simple. I saw someone else's recommendation at the time and decided to give it a try.

At that time, I opened a program and it always prompted that the DLL file was missing. After checking, I found that this problem is quite common, so I wanted to start with the System File Checker (SFC). The steps are very simple:

1. Open the Command Prompt (Admin): Right-click the Start menu and select "Windows Terminal (Admin)", or directly search for "cmd", and then right-click "Run as Administrator".
2. Run sfc /scannow: Type sfc /scannow in the command line and press Enter. At this time, the system will start scanning and repairing your system files. In fact, this process is a bit slow, and you have to wait patiently, but after it finishes scanning, it will automatically repair some damaged or missing files, including DLL files.
3. Restart the computer: After I ran it, I restarted the computer and opened the program again, and found that the missing DLL file was no longer prompted.

In fact, sfc /scannow is the most effective step for me to solve the problem of missing dll file on Windows 11. Although it may not work for everyone, at least in my experience, it works well. You can give it a try!

If the missing DLL error occurs when using a specific program, it often indicates that the program's installation is corrupted, incomplete, or the required DLL file is missing or damaged. Here's to fix Missing DLL files on Windows 11. Please the suggestions one by one.

Method 1: Reinstall the Program

This can replace missing or corrupted files, including the required DLL.

1. Go to Settings > Apps > Installed Apps.
2. Locate the program, click the three dots next to it, and select Uninstall. 
3. Download the latest version of the program from the official website. 
4. Reinstall the program and check if the DLL error is resolved.

Method 2. Repair the Program (if available) 

1. Some programs include a built-in repair feature that can fix issues without requiring a full reinstall. 
2. Go to Settings > Apps > Installed Apps.
3. Locate the program and click the three dots next to it. If a Modify or Repair option is available, select it and follow the on-screen instructions.
4. Restart your computer and check if the issue is resolved.

Method 3. Check for Program Updates

The missing DLL error might be caused by a bug or compatibility issue that has been fixed in a newer version of the program.

1. Open the program and check for updates in its settings or help menu.
2. Alternatively, visit the official website of the program to download and install the latest version.
3. Restart the program and see if the error persists.

If none of these steps resolve the issue, consider contacting the program's support team for further assistance. They may provide specific guidance or updates to fix the problem.