DllIconHandler

This project demonstrates how to create a Shell Icon Handler, that is loaded by Explorer.exe. An icon handler can show different icons for the same file type based on some logic. This implementation shows different icons for 64-bit and 32-bit DLLs.

(This project is used as one of the exercises in my .

Registration

The DLL is loaded and used by Explorer.exe. It must be properly registered, as it's as COM DLL and as a shell icon handler. To register it for all users, open an elevated command window, navigate to the directory where DllIconHandler.dll is located and enter the following:

regsvr32 DlliconHandler.dll

You should be greeted with a successful registration message box.

To register for the current user only, open a normal command window, navigate to the file's location and enter:

regsvr32 /n /i:user DllIconhandler.dll

You may need to restart explorer for the DLL to take effect. If you open a new explorer window that might work as well.

You can test it by opening an explorer window and navigating to c:\Windows\System32 and then contrast that with c:\windows\SysWow64.

Building from source

Open the solution file in Visual Studio 2022 and just build. You can also use an older Visual Studio version - just change the project's properties to use the toolset that you have installed.