在 https://winlibs.com/ 介绍到 C runtime 库时说：
Traditionally the MinGW-w64 compiler used MSVCRT as runtime library, which is available on all versions of Windows.
Since Windows 10 Universal C Runtime (UCRT) is available as an alternative to MSVCRT.
Universal C Runtime can also be installed on earlier versions of Windows (see: Update for Universal C Runtime in Windows).
Unless you are targetting older versions of Windows, UCRT as runtime library is the better choice, as it was written to better support recent Windows versions as well as provide better standards conformance (see also: Upgrade your code to the Universal CRT).
传统上，MinGW-w64编译器使用MSVCRT作为运行时库，该库在所有Windows版本上均可使用。然而，自Windows 10起，Universal C Runtime (UCRT)成为MSVCRT的一个可替代选项。UCRT不仅适用于Windows 10，也可安装在早期的Windows版本上，通过“Update for Universal C Runtime in Windows”更新获得。假如你的目标平台不是较老的Windows版本，选择UCRT作为运行时库更为优越，因为它旨在更好地支持最新Windows版本，并提供更佳的标准化符合性。因此，升级到Universal CRT对于优化代码以适应现代Windows环境和标准是非常推荐的。
现在 ucrt 作为windows 10 的一部分被包含在内，以前的版本需要下载软件包以获得支持。https://download.microsoft.com/download/C/5/D/C5D68AA1-F62E-422A-9084-4AD85CEB8D4D/WindowsUCRT.zip
标签：10,UCRT,通用,Windows,Universal,更新,Runtime,MSVCRT From： https://www.cnblogs.com/litifeng/p/18196857