1,204 questions
Visual C++ Redistributable Installation Directory
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BMC_dev_alawson
0
Reputation points
I have a long standing application built on Visual C++ 2008. Over the course of time, to help people who install it, we've implemented some "health checks" before installing to ensure C++ is installed on your system. What we're doing is checking in the %windir%\WinSxS* directory for the folder/files present to make sure the .dll's are present on the system.
We just tried installing this on a newer lab system, and have found that the C++ .dll's are installed in "C:\Windows\WinSxS\Fusion" directory (instead of the usual "side by side" WinSxS directory), which causes our application to produce a "false negative" response of "C++ isn't installed".
Can someone please help me understand how the C++ installer determines where it is going to install itself? I have the same installer that we've been using for the better part of a decade in my installer package, so I'm certain that whatever it is isn't hard coded in the installer. I've also double checked all of my system environment variables (at least the ones present in the System Properties application) and none of them are configured for this "fusion" directory.
I need to understand how this work so I can enhance my application to check for all of the right things.
Developer technologies | Visual Studio | Setup
Developer technologies | C++
3,973 questions
{count} votes
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David Lowndes 2,640 Reputation points MVP2023-10-25T17:57:58.33+00:00 Which specific C++ DLLs are you looking for?
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BMC_dev_alawson 0 Reputation points
2023-10-25T18:10:30.3066667+00:00 @David Lowndes Thanks for your response. Our "health check" code looks for 1 registry key, and 3 files:
amd64vc90ctr*
- msvcp*.dll
- msvcr*.dll
amd64vc90mfc*
- mfc*.dll
Those are the two folders and 3 files we look for. Your summary of my issue isn't accurate.
What I want to know, is HOW does the C++ installer determine where to write the files to? Because up until now they've always been written to C:\Windows\WinSxS_*** * *...._
But now, we're seeing some labs being written to C:\Windows\WinSxS\Fusion* * * * and we don't understand why there is a difference.
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David Lowndes 2,640 Reputation points MVP
2023-10-25T23:02:31.92+00:00 I don't know how the installer decides where to write the files to, but I guess the intention is that you shouldn't need to know - just let the redistributable installer do it's job. Why do you have your own checks, don't you install the redistributable with your application?
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BMC_dev_alawson 0 Reputation points
2023-10-25T23:12:21.65+00:00 End users expect checks - and with as many malware programs and other issues as we have in random server world, all programs do health checks during installations/upgrades. It's a normal industry standard. And we got it wrong or something has changed.
I need to understand the logic here.
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RLWA32 49,551 Reputation points2023-10-26T08:08:49.4066667+00:00 Does the Fusion subfolder in WinSxS only exist on Win 11 systems?
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Tianyu Sun-MSFT 34,441 Reputation points Microsoft External Staff2023-10-26T08:57:42.27+00:00 Hello @BMC_dev_alawson ,
Welcome to Microsoft Q&A forum.
Not very sure if the location is also related to system(different version of Windows OS).
From the perspective of installation, perhaps checking the Registry keys to confirm if the Visual C++ Redistributable package has been installed is better/easier. Do you consider checking Registry keys(HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\XX.0\VC\Runtimes(or VCRedist){x86|x64|arm64}, this Registry key stores the version number of the installed Visual C++ Redistributable packages)?
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BMC_dev_alawson 0 Reputation points
2023-10-26T13:05:42.6333333+00:00 Thanks @Tianyu Sun-MSFT , actually we do a lookup in "SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall" for "Visual C++" where the version is greater than "9", "0", "30729"... Then we look for files being present to confirm the installation.
The issue with the files, specifically the mfc file, is there are security vulnerabilities out on older versions of it and a lot of enterprise customers will lock the file or outright delete it. So we check the registry to see if the C++ is installed, then we check the file structure to make sure these key files are present in the system before we execute our program.
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