Because the C++ standard evolves. A program compiled with the 2015 toolchain expects a specific structure of std::vector and exception handling that is not binary-compatible with the 2010 runtime. Microsoft guarantees backward compatibility within the 2015-2022 family (version 14.x) but not across major generations.
| Version | Internal Version | Common Files | Primary Use Era | | :--- | :--- | :--- | :--- | | VC++ 2005 | v8.0 | msvcp80.dll , msvcr80.dll | Windows XP/Vista apps | | VC++ 2008 | v9.0 | msvcp90.dll , msvcr90.dll | Older games (e.g., Portal ) | | VC++ 2010 | v10.0 | msvcp100.dll , msvcr100.dll | Early 2010s software | | VC++ 2012 | v11.0 | msvcp110.dll , msvcr110.dll | Windows 8 era | | VC++ 2013 | v12.0 | msvcp120.dll , msvcr120.dll | Windows 8.1/10 early apps | | VC++ 2015-2022 | v14.x | vcruntime140.dll , msvcp140.dll | (2015-2024) | microsoft visual c++ runtime download
Thus, a typical modern gaming PC might have of the runtime installed side-by-side, all peacefully coexisting in C:\Windows\System32 . Part 3: The Only Safe Place to Download Critical warning: Never, ever download “Visual C++ Runtime” from third-party “DLL download” websites, cracked software repositories, or pop-up ads. These are common vectors for malware, rootkits, and trojans. Because the C++ standard evolves