Api-ms-win-core-windowserrorreporting-l1-1-1.dll May 2026
Many games and apps bundle old vcredist versions. Download the latest combined package from Microsoft:
Never manually delete, move, or rename system DLLs unless absolutely certain.
Most api-ms-win-core-*.dll files are API Sets (virtual dynamic link libraries). They act as an indirection layer—the Windows loader resolves them to the actual implementation DLL (usually kernel32.dll, kernelbase.dll, or ntdll.dll).
However, api-ms-win-core-windowserrorreporting-l1-1-1.dll is unusual because Windows Error Reporting (WER) is typically accessed through:
The -1-1-1 version suffix suggests a very specific, possibly internal or obsolete contract version.
Periodically run chkdsk /f to check for hard drive corruption.
Yes, this file is completely safe. It is an authentic Microsoft Windows system component. However, like many DLL files, it can be targeted by malware attempting to disguise itself. Always ensure that legitimate copies are stored in the correct system directories.
If SFC cannot repair the files, DISM can fix the underlying system image.
Steps:
If you are seeing errors regarding this file, do not download the DLL from a random "DLL Download" website. These sites often host malicious or outdated files.
Safe Solutions:
The file api-ms-win-core-windowserrorreporting-l1-1-1.dll is a core Windows Dynamic Link Library (DLL) that belongs to the Windows Error Reporting (WER) API set. It is primarily responsible for handling software crashes, hangs, and other application errors by collecting and sending report data to Microsoft for diagnosis. Why You Are Seeing an Error
Errors involving this file typically occur when launching games (e.g., Assassin's Creed Valhalla) or software on older operating systems like Windows 7 or Windows 8. Because this specific "l1-1-1" version of the file was introduced in later Windows updates (like Windows 8.1 or Windows 10), older systems often lack the necessary API "set" to run modern applications. Common Fixes
If you receive an error stating this DLL is missing, follow these steps to resolve it:
Update Windows: Ensure your operating system is fully up to date. Many modern "api-ms-win-core" DLLs are added to older systems through official Windows Updates.
Install/Repair Visual C++ Redistributables: This DLL is often a part of the Universal C Runtime (CRT). Downloading the latest Microsoft Visual C++ Redistributable (both x86 and x64) from the Official Microsoft Site often fixes the issue.
Run System File Checker (SFC): To repair corrupted system files, open the Command Prompt as Administrator and run:sfc /scannow. Api-ms-win-core-windowserrorreporting-l1-1-1.dll
Windows 7 Specific Fix: Users on Windows 7 may need to install KB3080149, which is an update for "Customer Experience and Diagnostic Telemetry" that includes several core error-reporting DLLs.
Upgrade your OS: If you are on Windows 8, upgrading to Windows 8.1 or Windows 10 is highly recommended, as many modern games and applications specifically require the updated API sets found in these versions. ⚠️ A Note on Safety
Never download individual DLL files from third-party "DLL fixer" websites. These files can be outdated, incompatible, or bundled with malware. Always use Official Microsoft Updates or redistributable packages to replace missing system components.
Are you getting this error while trying to launch a specific game or application?
api-ms-win-core-windowserrorreporting-l1-1-1.dll is a dynamic link library file that belongs to the Microsoft Windows "ApiSet" series. These files act as a "bridge" (redirection layer) between different versions of Windows, ensuring that modern applications can call standard system functions—in this case, related to Windows Error Reporting
When you see an error stating this file is "missing," it usually means an application was built using a newer Windows SDK or Visual Studio version and is trying to run on an environment that lacks the necessary runtime components. NI Community Common Causes for the Error Outdated Windows Version
: The system lacks the "Universal C Runtime" or specific Windows Updates required for modern API sets. Incomplete Visual C++ Redistributable
: The program depends on components that weren't installed or have become corrupted. Compatibility Issues Many games and apps bundle old vcredist versions
: Attempting to run a Windows 10/11-optimized program on Windows 7 or 8 without the proper compatibility patches. How to Fix the Error
To resolve the missing DLL issue, follow these steps in order: Install/Repair Visual C++ Redistributable Most "api-ms-win" errors are solved by installing the
Microsoft Visual C++ Redistributable for Visual Studio 2015, 2017, 2019, and 2022 . Download both the
versions, as many 64-bit systems still require the 32-bit (x86) files for specific apps. Run Windows Update This file is often delivered through the Universal C Runtime (CRT) update. Ensure your system is fully updated by going to Start > Settings > Update & Security > Windows Update Use System File Checker (SFC)
If the file is part of your OS but corrupted, Windows can repair it. Command Prompt as Administrator. sfc /scannow and press Enter. Reinstall the Problematic Program
The application itself may have had a corrupted installation. Reinstalling it often replaces the specific DLL links it needs to function.
Avoid downloading individual DLL files from "DLL fixer" websites. These files can be outdated, incompatible, or bundled with malware. Always use official Microsoft Support resources to update system libraries. Visual C++ version specifically matches the software you're trying to run?
missing "api-ms-win" dll in Teststand sequence - NI Community The -1-1-1 version suffix suggests a very specific,