notEcho, since I do not know what you have installed and uninstalled, I cannot give you advice on what is safe to delete or not. This is the rule of thumb: If you are not 100% sure, DO NOT delete it. Leaving the keys there, even if they are obsolete, will not slow your system down one nanosecond. You do not have to worry about the registry with Win 7. If you know that one of these keys you listed is referring to a program you have uninstalled and that it refers to nothing else, it is safe to delete it.