If you are installing CleanCache or Mozilla/Firefox for the first time or changing your profile directory from the two browsers, you will need to point CleanCache to your profile directory. Unfortunately neither browser stores your profile directory in an easily accessible place so I have to rely on some manual intervention to make sure the program is going to use the appropriate directory.
To set the profile directory, click on the Set Profile Directory button on either the Mozilla or Firefox Tabs. You will be presented with the following dialog:
From the Manage Profiles dialog you are able to add, remove and disable all of your profiles related to the browser where you clicked on the Set Profile Directory button.
To add a new profile just click on the Add button. You will be presented with the following dialg:
From this profile you can either browse to your profile directory (if it's not a default setup) or use the radio buttons on the right to select the version of Mozilla/Firefox that you are currently running. CleanCache will then find all of the profiles associated with the profile directory.
When you press save and then close, you will return to the Manage Profiles dialog. Now you may check which profiles you would like to clean.