MSVCRT40.DLL missing when installing software

Question

Hello all,

I'm trying to install a software that keeps giving me the message that "The file C:\Windows\System32\MSVCRT40.DLL could not be opened."

Searching the web I got the information that this DLL is part of the Visual C++ packages. Which one do I need to download to fix this? I have installed already Visual C++ 2013 Redistributable 12.0.30501 and 12.0.40649 and Visual C++ 2015-2019 Redistributable 14.28.29914.

Answer 1

Thank you for reaching out

MSVCRT40.DLL is not included in modern Visual C++ Redistributable packages. This DLL belongs to the legacy Visual C++ 4.0 runtime, which predates the redistributables starting from Visual Studio 2005 onward. If your software depends on MSVCRT40.DLL, installing newer redistributable like 2013 or 2015–2019 won’t help.

If you need to restore this DLL manually, you can download it from a trusted source.

Make sure to scan the file before use and place it in C:\Windows\System32 or C:\Windows\SysWOW64 depending on your system architecture.

Answer 2

First and foremost, what version of Windows is this being installed on, and what is the bitness? The big issue is, for modern Windows, this file exists and it is exclusively a forwarder to the Windows internal CRT and C++ runtime.

Now, I know that the screenshot that I provided is SysWOW64, but the important thing is that for 64 bit Windows, this is the 32 bit library directory. When a 32 bit process runs, Windows will redirect any access to System32 to SysWOW64, because contrary to its name, System32 is the 64 bit library directory. Since there is also only 64 bit versions of Windows 11, then this file will only exist in SysWOW64 now.

It is expected for msvcrt40.dll to not exist in System32 itself, there was never a 64 bit version of Visual C++ 4.0, so there was never a 64 bit version of the library.

So to recap, check SysWOW64 for msvcrt40.dll, it should exist. If it doesn't, then check your Windows' integrity using SFC since this indicates that files are missing. If the file exists and the software keeps complaining, then use process monitor (procmon) to check what path the application is checking. If it is checking System32, then the software is either using a custom import library for 64 bit, or it has disabled file system redirection. This is the responsibility of the software developers to fix by either providing a corresponding version of the library or checking the proper path on 64 bit Windows.

Answer 3

Hello everyone.

I ended up installing dotnetfx35 and it solved the issue.

Thanks for the help everyone.