Since i'm new to CCleaner and i have come up with all these issues i wanted to know is it safe to delete all uninstaller reference issues, activeX/COM issues, missing shared DLL, open with application issues, application path issues, uninstaller reference issues, missing startup software and missing MUI reference issues registery keys after making backups.Also is it true that one should not remove the registry keys for all unused file extensions for you never know when you need them later?