Windows applications depend on specific runtime files to function correctly. When the Mfc120u.dll file disappears from your system, you’ll see error messages preventing programs from launching. This component belongs to Microsoft’s Visual C++ library and affects software like Adobe Lightroom, Google Chrome, and various development tools.
The error typically appears when starting applications that require Visual C++ 2013 runtime libraries. Programs refuse to open until you restore the missing component. Your system stores this file in the System32 directory by default, where applications access it during startup.
What Causes Mfc120u.dll Errors
Missing Visual C++ Redistributable packages account for most cases. When you install Windows fresh or remove certain programs, these essential libraries get deleted. Malware sometimes targets DLL files, corrupting or removing them to disable security software.
Incomplete software installations leave behind broken registry entries. Applications may fail to register Mfc120u.dll properly during setup. Hard drive corruption also damages system files, making them unreadable for dependent programs.
Install Visual C++ 2013 Redistributable
Visit Microsoft’s official download page for Visual C++ Redistributable Packages. Download both vcredist_x64.exe and vcredist_x86.exe files regardless of your system architecture. Many applications require both versions to function properly.
Run each installer separately with administrator privileges. The setup wizard will complete within minutes. Restart your computer after both installations finish to register the components correctly.
Verify and Repair Game Files
Steam and other gaming platforms include built-in repair tools. Right-click the affected game in your library and select Properties. Navigate to the Local Files tab and choose “Verify integrity of game files.”
This process scans installation folders and replaces corrupted components automatically. The verification takes several minutes depending on game size. Similar to fixing DLL files in general, this method works across different platforms.
Run System File Checker
Open Command Prompt as administrator by searching for cmd and selecting “Run as administrator.” Type sfc /scannow and press Enter to start the scan. Windows will examine protected files and restore any damaged components.
The scan takes 15-30 minutes to complete. Don’t interrupt the process or restart your computer during verification. After completion, run DISM /Online /Cleanup-Image /RestoreHealth for comprehensive repairs.
Reinstall the Problematic Application
Navigate to Settings and open Apps. Locate the program displaying the Mfc120u.dll error in your installed applications list. Click Uninstall and follow the removal wizard.
Download a fresh installer from the official website. Run the setup and complete all installation steps. This approach works when fixing MSVCP140.dll and similar runtime library errors.
Check for Windows Updates
Press Windows + I to open Settings. Select Update & Security and click “Check for updates.” Microsoft distributes runtime library fixes through regular patches.
Install all available updates before restarting. Pending updates sometimes prevent proper DLL registration. Your system needs current security patches to maintain file integrity.
Use System Restore
Type “System Restore” in the Windows search bar and press Enter. Select a restore point created before the Mfc120u.dll error appeared. Click Next and confirm your selection.
Windows will revert system files while preserving personal documents. The process takes approximately 30 minutes. System Restore helps when recent installations or updates triggered the problem, just like when troubleshooting ntdll.dll errors on Windows systems.
Copy File from Another Computer
Locate a working Windows computer with the same version and architecture as yours. Navigate to C:\Windows\System32 and search for Mfc120u.dll. Copy the file to a USB drive.
Paste the file into your System32 directory. You’ll need administrator permission to complete this operation. Restart your computer to register the newly copied component.
FAQs
Can I download Mfc120u.dll from third-party websites?
Avoid downloading DLL files from random websites because they frequently contain malware or outdated versions. Install the official Visual C++ Redistributable from Microsoft instead. This method ensures you get all required components with proper digital signatures and security verification.
Why does Mfc120u.dll error affect multiple programs?
The Mfc120u.dll file is a shared library component used by numerous applications built with Visual Studio 2013. When this single file goes missing, all programs depending on it fail to launch. Installing the redistributable package fixes the error across all affected software simultaneously.
Will reinstalling Windows fix Mfc120u.dll errors permanently?
A clean Windows installation replaces all system files including Mfc120u.dll. However, this represents an extreme solution requiring several hours and complete data backup. Try simpler fixes like installing Visual C++ packages first before considering full reinstallation of your operating system.
Do 64-bit systems need both x86 and x64 redistributable packages?
Yes, 64-bit Windows runs both 64-bit and 32-bit applications. Many programs use 32-bit code even on 64-bit systems. Installing both vcredist_x86.exe and vcredist_x64.exe ensures compatibility across all software types. This prevents errors in applications built for either architecture.
Can antivirus software cause Mfc120u.dll to disappear?
Security programs sometimes quarantine or delete DLL files mistakenly identified as threats. Check your antivirus quarantine folder and restore Mfc120u.dll if present. Add the file to your security software’s exception list to prevent future removal, similar to addressing Msvcr100.dll errors caused by overzealous scanning.
