I have built a shell extension handler, using this as a template:


In this instance, it registers with a ".ts" extension:

        hr = RegisterShellExtContextMenuHandler(L".ts",  

The project compiles fine, and the registration works also.

But on one PC, it fails to load (the context menu for .ts files is not updated), and on another (both using Win7 x64) it does.

I tried 2 others handlers, with '.mkv' and '.mp4' extensions (using of course different CLSIDs), and the results are random. Some work on a given PC, and some not.

I have no clue what prevents one handler to load on a PC, while it loads on another.

Any help would be greatly appreciated.

I found a workaraound: making a generic handler for all extensions, and having it test the extension for the selected files to chose what items to add to the context menu.

This handler always load.