I have a Startup entry - Enabled - No - Key - Startup Common - Program - Sony MSS.Ink - Context Menu - Blank - User - All Users - C:\Program files (x86) Sony\MSS\3.0.271\SSScheduler.exe that I can't delete from CCleaner.
All the Sony files have been deleted from the Sony laptop and most have been removed from the Registry. Sony have long stop making computers and offering upgrades and all their software is obsolete. I had issues and did a complete re-installation of the O/S back to Windows 8 and then to the latest version of Windows 10 Home Edition.
How do I remove this one entry in CCleaner? It has been disabled.
If you right-click on the entry in CCleaner start up list and select either 'open containing folder' or 'open in regedit' which may help you to decide what to do next.
If it's a locked registry key you'd need to modify the Permissions to Full Control to allow you to delete it either via CCleaner or RegEdit.
Maybe see this topic about Malwarebytes AdwCleaner v7.4 now having the ability to remove OEM bloatware, i.e.; files and registry keys:
https://forum.piriform.com/topic/54508-adwcleaner-74/
The option to right click only gives the option to delete the entry and that it won't do. I suspect it will remain there. I have deleted all references to Sony MSS out of the registry.