Mfc100.dll errors are caused by situations that lead to the removal or corruption of the mfc100 DLL file.In some cases, these errors could indicate a registry problem, a virus or malware issue, or even a hardware failure.

The mfc100.dll error message could apply to any program or system that might utilize the file on any of Microsoft's operating systems, including Windows 11, Windows 10, Windows 8, etc.

How to Fix Mfc100.dll Errors

Follow these steps in the order they're given below to try the simpler solutions first.

Don't download mfc100.dll from a "DLL download" website. There are many reasons why downloading DLL files like that is a bad idea. If you need a copy of this file, it's best to obtain it from its original, legitimate source.

1. Download the Microsoft Visual C++ 2010 Service Pack 1 Redistributable Package MFC Security Update and run it. This will replace/restore the mfc100.dll with the most recent copy provided by Microsoft.

   You're given a few download options from Microsoft for this update, based on the version of Windows you have installed: x86 (32-bit) or x64 (64-bit). If you need the 32-bit version, download the file calledvcredist_x86.exe. The 64-bit version is named vcredist_x64.exe.

   It's been reported by some users that select programs require the 32-bit install even though you're running a 64-bit version of Windows. Keep that in mind if completing this step doesn't fix the problem.

   Most people can ignore the vcredist_ia64.exeoption (the one with "ia" in the name) since it's only relevant for Itanium CPUs which are normally used only on server hardware.

   Start Windows in Safe Mode to complete any of these steps if you're unable to access Windows normally due to the error.

2. Restore the file from the Recycle Bin. The easiest possible cause of a "missing" mfc100.dll file is that you've mistakenly deleted it. If you suspect this, but you've already emptied the Recycle Bin, you may be able to recover it with a free file recovery tool.

   

   Recovering the file this way is a smart idea only if you're confident you've deleted the file yourself and that it was working properly before you did that.

3. Run the sfc /scannow System File Checker command to replace a missing or corrupt copy of the mfc100.dll file. This DLL file is provided by Microsoft, so System File Checker should restore it.

4. Run a virus/malware scan of your entire system. Some mfc100.dll errors could be related to a virus or other malware infection on your computer that has damaged the DLL file. It's even possible that the error you're seeing is related to a hostile program that's masquerading as the file.

5. Use System Restore to undo recent system changes. If you suspect the error was caused by a change made to an important file or configuration, System Restore could solve the problem.

6. Reinstall the program that's producing the mfc100.dll error. If one of these errors occurs when you use a particular program, reinstalling that program might help.

7. Test your memory and then test your hard drive. I've left the majority of hardware troubleshooting to the last step, but your computer's memory and hard drive are easy to test and are the most likely components that might cause mfc100.dll errors as they fail.

   If the hardware fails any of your tests, replace the memory or replace the hard drive as soon as possible.

8. Repair your installation of Windows. If the individual troubleshooting advice above is unsuccessful, performing a startup repair or repair installation should restore all Windows DLL files to their working versions.

9. Perform a clean installation of Windows. This will erase everything from the hard drive and install a fresh copy of Windows. If none of the steps above correct the mfc100.dll error, this should be your next course of action.

   All the information on your hard drive will be erased during a clean install. Make sure you've made the best attempt possible to fix the mfc100.dll error using a troubleshooting step prior to this one.

10. Troubleshoot for a hardware problem if any errors persist. After a clean install of Windows, your DLL problem can only be hardware related.

Need More Help?

If you don't think fixing this problem yourself is working out too well, see How Do I Get My Computer Fixed? for a full list of your support options, plus help with everything along the way like figuring out repair costs, getting your files off, choosing a repair service, and a lot more.

Causes of Mfc100.dll Error Messages

There are several ways mfc100.dll errors can show up on your computer, such as:

Mfc100.dll Not Found

This application failed to start because mfc100.dll was not found. Re-installing the application may fix this problem.

Cannot find [PATH]\mfc100.dll

This program can't start because mfc100.dll is missing from your computer.

The file mfc100.dll is missing.

Cannot start [APPLICATION]. A required component is missing: mfc100.dll. Please install [APPLICATION] again.

Paying close attention to when you see the error is helpful. These error messages might appear while using or installing certain programs, when Windows starts or shuts down, or maybe even during a Windows installation.