Is it possible to save the list of 'Cookies to Keep' before CCleaner uninstalling for transfering to new os (windows)?
If you go to Options > Advanced you will see an option to 'Save all settings to INI file'
Ticking this means that a file called ccleaner.ini is created, and maintained, in your C:\Program Files\CCleaner folder.
This file contains all your current CCleaner settings, including 'cookies to keep'.
(Be aware that if you create this file and then later delete for whatever reason, CCleaner will reset to the default settings next time it is run; presumably because it's looking for the .ini and can't find it).