api-ms-win-crt-runtime-l1-1-0.dll Missing Error

The error api-ms-win-crt-runtime-l1-1-0.dll is missing indicates the Universal C Runtime (UCRT) is not installed, usually fixed by installing Windows updates. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Part of the Universal C Runtime (UCRT) included in Windows 10+. On Windows 7/8, requires KB2999226 update to be installed. Common after clean installs of older Windows without running updates. Required by modern Visual C++ applications and Python. The DLL is an API set forwarder, not a traditional DLL file. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Windows 7/8.1 missing KB2999226 (Universal CRT) update. Windows Update service disabled preventing automatic installation. Corrupted Windows Update components blocking KB2999226. Clean Windows installation without subsequent updates. Visual C++ Redistributable installed before UCRT prerequisite. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: On Windows 10/11: run Windows Update to ensure all updates are installed. On Windows 7/8: download and install KB2999226 from Microsoft Update Catalog. If KB2999226 fails, install KB2919355 first (prerequisite on Windows 8.1). Reinstall Visual C++ 2015-2022 Redistributable after installing the UCRT update. Run sfc /scannow to repair system file integrity. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Windows Error Codes collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.