CyberLink Media Library is an application that runs in the background if you use certain programs from CyberLink. Its main purpose is to organize and track your media files so that the main CyberLink software can work better. If CyberLink Media Library may cause problems or slows performance, you can disable it from running automatically.
CyberLink Media Library isn't a standalone application, nor indeed one you would usually choose to actively run. Instead it runs automatically when you use other CyberLink software, such as their playback, editing and disc-burning applications. Media Library helps these applications find relevant media files more quickly. If you do encounter CyberLink MediaLibrary it will be in the form of its file CLMSvc.exe, which may be mentioned in error messages or in TaskManager.
If you receive an error message about CyberLink Media Library, you can close it in the processes section of Task Manager, which you can open in Windows 8.1 by pressing "Ctrl-Shift-Esc." If you're repeatedly receiving errors, you may need to reinstall your CyberLink software. You can also use Task Manager's Startup section to stop CyberLink Media Manager from running automatically when you start up your PC. This may make your PC run more smoothly at startup, though it could result in a slight delay when you launch CyberLink software.