Doesn't work

So VDownloader stopped working, I've tried uninstalling it and re-installing it but after uninstalling it it says that there were components not removed that could be removed manually, although I don't know what that means or how to do it. After the download it just says it has stopped working and then saying I need to close the program. I have been trying to get this rectified for months now with no answers in sight. I was given a product key but I have nowhere to use it. When it downloads it says I'm using version 5.0.4277