Fixing the api-ms-win-crt-runtime-l1-1-0.dll Error in Windows

What the api-ms-win-crt-runtime-l1-1-0.dll Error Means

When attempting to launch a game or application, a dialog box appears on the screen with the message: "The program can't start because api-ms-win-crt-runtime-l1-1-0.dll is missing from your computer. Try reinstalling the program to fix this problem." This library is part of the Universal C Runtime (UCRT) component, which handles basic I/O functions, memory management, and mathematical computations in applications compiled with Visual Studio 2015 and later. Without it, the executable simply cannot initialize the required dependencies and crashes during the startup phase.

Common Causes

The error is rarely caused by a faulty application itself. More often, the root cause lies in the state of the operating system:

• Missing Visual C++ Redistributable 2015-2022 package. Windows 10/11 includes UCRT by default, but on Windows 7/8.1 it must be installed separately.
• Missing system update KB2999226. This specific patch delivers the Universal C Runtime to earlier OS versions.
• Corrupted system files following an improper shutdown, power failure, or antivirus software accidentally quarantining the DLL.
• Library version conflicts, where multiple applications attempt to use different builds of the same dependency.

How to Fix It

Method 1: Install the Official Visual C++ Redistributable Package

The fastest and safest method is to install the latest Microsoft library package. It will automatically register the missing file in the registry and system directories.

1. Go to the official Microsoft support page and locate the "Latest supported Visual C++ Redistributable" section.
2. Download the installer that matches your system architecture. If you are running 64-bit Windows, download both files: vc_redist.x64.exe and vc_redist.x86.exe. Many 64-bit applications still rely on 32-bit libraries.
3. Run vc_redist.x86.exe, accept the license agreement, and wait for the installation to complete.
4. Repeat the process for vc_redist.x64.exe if you downloaded it.
5. Restart your computer and test launching the application.

💡 Tip: After installation, verify that "Microsoft Visual C++ 2015-2022 Redistributable" entries appear in "Programs and Features" (or "Apps & features").

Method 2: Manually Install Update KB2999226

If Windows Update is disabled or failing, you can deploy the component manually. This method is particularly effective on Windows 7 and 8.1.

1. Open Control Panel and navigate to "System and Security" → "System" to accurately identify your OS version.
2. Visit the official Microsoft Update Catalog and download the KB2999226 package matching your architecture (x64 or x86) and Windows version.
3. Run the downloaded .msu file as an administrator.
4. Follow the installation wizard prompts and wait for the system to restart.

Method 3: Repair System Stores Using DISM and SFC

If the package is already installed but the system still cannot locate the file, the component store is likely corrupted. Built-in Windows utilities can restore the original DLL versions.

1. Press Win + X and select "Terminal (Admin)" or "Command Prompt (Admin)".
2. Enter the following command to check system integrity and press Enter:

sfc /scannow

3. Wait for the scan to complete (usually 5–10 minutes). If the utility reports that it found and repaired files, restart your PC.
4. If the issue persists, run the system image repair command:

DISM /Online /Cleanup-Image /RestoreHealth

5. Once DISM completes successfully, run sfc /scannow again to finalize the repairs.

⚠️ Important: Do not turn off your computer while DISM is running. Interrupting the process may cause Windows Update to become unstable.

Prevention

To prevent the api-ms-win-crt-runtime-l1-1-0.dll error from recurring, follow basic system maintenance practices. Regularly install Windows cumulative updates, as they include the latest UCRT library versions. When installing new software or games, look for checkboxes like "Install Visual C++ Redistributable" in the installers (launchers like Steam and Epic Games often handle this automatically). Avoid using unofficial "DLL downloaders" or third-party repackagers, as they frequently break dependency chains and can interfere with Windows Defender's security mechanisms.