XP System Restore won't restore after I used CCLeaner. I checked that System Restore is turned on. How can I get System Restore to go back to an earlier restore point even if CCleaner did not cause this problem?

I don't know if CCleaner could have caused your problems or not.

Unfortunately there are some instances when System Restore can't restore a system to a previous date. It's one reason by itself to also adopt ERUNT since it will daily make known good registry backups and it's often recommended on these very forums since it can literally be a system saver when System Restore fails.