For Windows versions older than Windows 10 (e.g., Windows 7, 8, 8.1), the UCRT must be installed manually via:
Since Windows 10 version 1507+, UCRT is in-box (pre-installed).
On Windows 10 or 11, simply:
dir C:\Windows\System32\ucrtbase.dll
You should see the file present.
The CRT code is copied directly into your .exe or .dll file. microsoft c runtime
Historically, standard C functions (like strcpy) were prone to buffer overflow vulnerabilities. Microsoft addressed this by introducing "Secure CRT" functions, often denoted with an _s suffix.
Note: These functions are part of the CRT but are technically Microsoft extensions (though some have been adopted into optional parts of the C11 standard). For Windows versions older than Windows 10 (e
The compiler extracts the necessary CRT functions and embeds them directly into your .exe or .dll file.
The Developer’s Dilemma: Static linking offers convenience and portability. Dynamic linking offers better system integration and security. Most professional software that expects to be installed properly uses dynamic linking and relies on the installer to deploy the Visual C++ Redistributable. Since Windows 10 version 1507+, UCRT is in-box
The compiler tells the executable to look for the CRT functions in a separate DLL (e.g., ucrtbase.dll) at runtime.