From what you said in another thread, dopusx64.exe doesn't seem to have been uninstalled at all on your system. I'm not sure why and haven't seen it happen myself.
If you regularly use CCleaner and similar, something in the registry may have been "cleaned" incorrectly and that thing may have been what the Opus 10 installer uses to detect whether or not it needs to uninstall dopusx64.exe from an Opus 9 installation. Registry cleaners do more harm than good.
Feel free to delete the registry values. Nothing will use them, either way as nothing in Opus 10 uses dopusx64.exe and nothing outside of Opus knows it exists.
This may seem like a truly simple minded approach – that's me all over – but one way in which I have deleted this sort of garbage in the past is to reinstall and remove the software that created the settings in the first place, rebooting at every possible opportunity.
Of course, this may also mean removing Opus 10 before you go down this path, saving settings before you do it, but some people prefer that to messing around in the registry.