Hi,
I have just re-installed OS X (10.8.5) on my MacBook and have also re-installed CCleaner Pro.
Now, despite re-entering my registration details correctly, EVERY TIME I launch CCleaner, the "registration window" appears and it asks for my registration details again.
I have definitely entered my details correctly, but every time I launch CCleaner it continues to display the registration window!!
However, If I click "cancel", CCleaner opens and functions normally, although it displays my copy as being "unregistered", despite it being a bona fide copy, purchased from Piriform online.
Can anyone help please?