I know for sure that cccleaner can remove system restore points. can I safely delete one of them? Am I risking something in deleting one or more of them, if the system restore doesn't work at all I don't know the reason)?
They are to protect you in case you make a change that undermines your system, you can go back to before you made the change. If you are happy with they way your system works, it is my understanding that you can leave the last 2/3? and delete the rest.