C++ move dll files from root to sub folder

Question

I'm making a program in visual c++. The program relies on some dll files, which I don't want to place in system32. Now the dll files is in the same folder as my .exe, but i would like to move them to a sub folder. The problem is, if I move the files, my application fails to start and comes with this error message:

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MyProgram.exe - Unable to Locate Component

This application has failed to start because myDll.dll was not found. Re-installing the application may fix the problem.

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I have had the same problem before, where if found a solution, which included adding something to the registry, but i forgot how it worked, and now I can't find the guide again.

Can someone please help me?

Answer 1

I believe this is the article you are looking for:

http://www.codeguru.com/Cpp/W-P/dll/article.php/c99

Each application can now store it own path the registry under the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths

The use the application path, set a key for your application, using ONE.EXE from the example above:

HKEY_LOCAL_MACHINE...\CurrentVersion\App Paths\ONE.exe

Set the (Default) value to the full path of your executable, for example:

C:\Program Files\ONE\ONE.exe

Add a sub-key named Path

Answer 2

Sounds like you're after the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths key. See here for complete information. In short, a string called Path points to a DLL search path. For example if your application was called "MyApp" a .reg file like this would do the trick:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\AppPaths\MyApp.exe]
@="C:\\Program Files\\MyCompany\\MyApp\\MyApp.exe"
"Path"="C:\\Program Files\\MyCompany\\MyApp\\DLLs"

Answer 3

There is more than one way to solve this problem. As other mentioned you can modify search path for your application in registry. Sometimes, you don't have rights to write to the registry, or you cannot do it for other reasons, then you can set dll path explicitly, the WinAPI function for that is SetDllDirectory, see MSDN.