Thank you for posting the screenshot. It was very helpful.
For the non-French speaking folks who may come across this post, the error is "Flash Player ActiveX Control fails to register".
The registration error is usually returned when there are permissions issues in either the registry or the file system where Flash Player is installed to. Please see the FAQ How do I fix Windows permission problems with Flash Player? or the tech note Flash Player | Windows registry permissions. The FAQ includes a video on running the fix while the tech note contains more detailed information on the permissions issue.