If you are seeing an error that api-ms-win-core-windowserrorreporting-l1-1-1.dll is missing, it is likely because a program is trying to access Windows Error Reporting (WER) functions that aren't properly installed or updated on your system.
This specific file is a Dynamic Link Library (DLL), part of the Windows "ApiSet". It acts as a bridge, allowing software built with modern development tools like Microsoft Visual Studio 2015 to communicate with the Windows operating system. Common Error Messages
"The program can't start because api-ms-win-core-windowserrorreporting-l1-1-1.dll is missing from your computer."
"The code execution cannot proceed because api-ms-win-core-windowserrorreporting-l1-1-1.dll was not found."
"There was a problem starting api-ms-win-core-windowserrorreporting-l1-1-1.dll." How to Fix the Missing DLL Error
Avoid downloading the DLL from random "DLL fixer" sites, as these files can be outdated or carry malware. Instead, use these official methods to restore the file: 1. Install or Repair Microsoft Visual C++ Redistributable Api-ms-win-core-windowserrorreporting-l1-1-1.dll
This is the most frequent cause for this error. Most programs need the Visual C++ Redistributable for Visual Studio 2015 (or later) to function.
Api-ms-win-core-windowserrorreporting-l1-1-1.dll is a "virtual" DLL file that is part of the Windows API Set
, specifically used for Windows Error Reporting (WER) functions. Because it is a virtual module, it often does not exist as a physical file on older operating systems, which is why users frequently report it as "missing" when trying to run modern applications or games on older versions of Windows. Microsoft Learn Common Causes for the Error Operating System Incompatibility:
The software you are trying to run requires a version of the Windows API Set only present in Windows 10 Windows 11 Legacy OS Usage:
Running modern apps on Windows 7, 8, or 8.1 often triggers this error because these systems lack the updated API sets. Missing Dependencies: The program may depend on a specific Microsoft Visual C++ Redistributable that hasn't been installed. How to Fix the Error Upgrade to Windows 10 or 11 Forensics and diagnostics
Since this DLL is native to modern Windows versions, the most effective fix is upgrading your operating system. Install the Universal C Runtime (CRT) If you are on an older Windows version, ensure you have the Update for Universal C Runtime in Windows
installed. This package provides many of the missing "api-ms-win-core" functions to legacy systems. Install/Repair Visual C++ Redistributables Download the latest versions from the Microsoft Support Page
. Many games and apps rely on these packages to bridge API gaps. Run in Compatibility Mode Right-click the application's Properties Compatibility
Check "Run this program in compatibility mode for:" and select Run System File Checker (SFC)
If you are already on Windows 10/11 and seeing this error, your system files might be corrupted. Command Prompt as Administrator. sfc /scannow Important Safety Warning If an app triggers WER behavior but reports don’t appear:
Do not download this DLL from third-party "DLL fixer" websites.
These files are often bundled with malware or may be incompatible with your system architecture, leading to further instability. Always use official Microsoft Update or Redistributable links. Are you seeing this error while trying to launch a specific game older software on Windows 7 or 8?
As a last resort, you can refresh Windows without losing personal files.
In-Place Upgrade (preserves apps and data):
Upgrade this PC nowReset This PC (more aggressive):
Settings > Update & Security > RecoveryReset this PC, click Get startedKeep my filesNever manually delete, move, or rename system DLLs unless absolutely certain.