The first time I saw that in CCleaner it frightened me to death, Happy

All those are the hidden temp files and hidden internet files, and cookies, and other things that know one tells you about.

As long as you have looked at the selection options on that page, and understand what will be deleted, then that's fine.

One thing, if you want to see what cookies are about to be deleted, goto Options then Cookies. You can move the cookies you do not want to be deleted to the right hand side.