What is msdia80.dll in my partition drive "H" and is it safe to delete it?

I got the same "Module failed to load" error as the poster above. There is an error (more than one actually) in the article describing the process (http://support.microsoft.com/kb/927665).

It says to type this line at the command prompt:

regsvr32 driver:\Program Files\Common Files\Microsoft Shared\VC\msdia80.dll

where "driver" is replaced with the drive letter where the user's Program Files folder is located. ("driver" is a typo in the example of the command, it should be "drive" so it matches the instruction on where to move the file.) But Command Prompt treats the space after the word "Program" in the command as the end of the command (at least it does in Windows 8.1).

The path must be contained in quotation marks, like this:

regsvr32 "driver:\Program Files\Common Files\Microsoft Shared\VC\msdia80.dll"

Then it works.

I hope that helps others who are dealing with the frustration of a poorly-edited article.

Hi Nsriyas,

The msdia80.dll file is a system file in Visual C++ and some other Windows based software applications.

Have you installed Visual C++ Redistributable Package on this computer?

You have a computer that is running a 64-bit operating system. You install the Microsoft Visual C++ 2005 Redistributable Package on this computer by using the Vcredist_x64.exe file or the Vcredist_ia64.exe file. When you do this, the Msdia80.dll file is installed in the root folder of the boot drive.

If you have installed Visual C++ in a different drive, then, it could have happened that the file is moved. In that case, I would suggest you to move the Msdia80.dll file to the Drive:\Program Files\Common Files\Microsoft Shared\VC folder. Then, use command prompt to register the Msdia80.dll file.

Follow the steps:

a)      Type cmd on the Start screen and right click on Command Prompt.

b)      Select “Run as administrator”. Type the following command and hit Enter:

regsvr32 driver:\Program Files\Common Files\Microsoft Shared\VC\msdia80.dll

If you have already uninstalled Visual C++ and the file is located in a different drive after uninstalling it, then, you can delete the file.

For reference, you can take a look at the article:

FIX: The Msdia80.dll file is installed in the root folder of the boot drive when you install the Visual C++2005 Redistributable Package by using the Vcredist_x64.exe file or the Vcredist_ia64.exe file

http://support.microsoft.com/kb/927665

Note: This link has information related to Visual C++ 2005 Redistributable Package which might not be compatible to Windows 8.

Please let us know if you need more assistance on this issue. We will be glad to help you.

Thank you very much for the information, the problem was solved, in my case "driver" is C:

regsvr32 "C:\Program Files\Common Files\Microsoft Shared\VC\msdia80.dll"

saludos from México

The OS is Windows 10

I got the same "Module failed to load" error as the poster above. There is an error (more than one actually) in the article describing the process (http://support.microsoft.com/kb/927665).

It says to type this line at the command prompt:

regsvr32 driver:\Program Files\Common Files\Microsoft Shared\VC\msdia80.dll

where "driver" is replaced with the drive letter where the user's Program Files folder is located. ("driver" is a typo in the example of the command, it should be "drive" so it matches the instruction on where to move the file.) But Command Prompt treats the space after the word "Program" in the command as the end of the command (at least it does in Windows 8.1).

The path must be contained in quotation marks, like this:

regsvr32 "driver:\Program Files\Common Files\Microsoft Shared\VC\msdia80.dll"

Then it works.

I hope that helps others who are dealing with the frustration of a poorly-edited article.

Thank you mycranium. So just to reiterate for those others who've had trouble - the following worked with driver/drive replaced with the actual drive letter of course, as per mycranium's instructions.

regsvr32 "C:\Program Files\Common Files\Microsoft Shared\VC\msdia80.dll"

​Hi Nsriyas,

I appreciate the efforts which you have put to try and fix the issue till now.

I would suggest you to post the same query on Microsoft Visual C++ forum for further assistance. Refer to the link:

https://social.msdn.microsoft.com/Forums/vstudio/en-US/home?forum=vcgeneral

Please let us know if you have more queries on Windows.