Home Forums Tech Helproom ccleaner wipe free space segment Forum Rules | Contact Forum Editor | Report a Post ccleaner wipe free space segment KEITH 1955 17:49 20 Sep 2018 Locked ok guys so you may think this is a dumb question but I honestly don't know the answer. What exactly does the wipe free space segment of the program do , does it do a kind of defrag to close up empty spaces and if so do I need to do it on an ssd. wee eddie 18:35 20 Sep 2018 As I understand it, the free space is that which has no files on it. However, it could be full of deleted files. It is they that will be overwritten john bunyan 18:43 20 Sep 2018 The more passes you choose the longer it takes - could be many hours. Sort of thing you do if selling. PC where you can keep the OS etc, delete your data and wipe the space. Not worth the bother for your PC on a day to day basis. Fruit Bat /\0/\ 21:37 20 Sep 2018 It overwrites with zeros, the space which windows has allocated as free space available to write files on. If you delete a file windows just removes the first digit of the file name and removes it from the index thus windows no longer sees a file at that point. This is why recovery software can get data back. CCleaner overwrites the space with zeros, to securely delete you need a minimum of 3 passes, I have recently recovered files after a one pass with CCleaner. KEITH 1955 21:52 20 Sep 2018 thanks for your answers guys ! This thread is now locked and can not be replied to.