Are Visual C++ dynamic runtime libraries part of the Windows OS nowadays?

Question

Are the dynamic runtime libraries for Visual C++ (more specifically 2008) part of the Windows OS nowadays? I noticed that at least on Windows 8 you no longer need to ship these with your application or have the user install the redistributable package from Microsoft.

Is this true? If so, for what Windows versions and for what versions of Visual C++ does this apply to?

Answer 1

No, they've never been part of the Windows distribution. Deploying them yourself is a hard requirement.

It certainly may seem that they are. Starting with msvcrt.dll in the system32 directory, it has the same name as the C++ runtime dll in Visual Studio versions prior to VS2002 (VS6 and earlier). It is however a private copy of the CRT that is used by Windows executables. And protected by the File System Protection feature in Windows, preventing old installers from destroying the operating system.

It certainly often works by accident. There are many programs that need the Microsoft CRT so it isn't unlikely that the user has run an installer before that got the DLLs installed. Clearly you cannot depend on that common accident.

Similarly for Windows 8, the pre-installed Microsoft.VCLibs.110 package matches the package you need for a Store app written in C++. But that's for the same reason as above, Microsoft Store programs were also built with VS2012, just like yours. What's going to happen in the upcoming VS2013 is a bit muddy right now, we'll know soon.

Answer 2

In my opinion, the answer would be both: Yes and No.

• Yes: More recent Windows OS are generally shipped with VC runtimes pre-installed (along with more recent versions of the .NET framework). It is because Microsoft uses the latest/newer Visual Studio before they release VS to the public (or even to MSDN subscribers). If not this way, whenever you install some application (legacy application or some downloaded application), the setup would anyway install the required VC++ runtime. Another way is through automatic updates.
• No: In case where none of the above mentioned rules applies. Or, when the VC runtime shipped with a new service pack or a patch. You might have developed your application with newer patch/SP, and that must be installed (as Side-by-Side, of course).