||When CCleaner Network cleans, you can specify whether it deletes files normally (using standard Windows techniques), or whether it uses secure file deletion. In order of security, the secure file deletion options are simple overwrite, DOD 5220.20-M, NSA, and Guttman.
||The higher the security level, the longer the clean process will take.
|Wipe Alternate Data Streams
||In NTFS file systems, alternate data streams store extra information about files. For example, if you have an image picture.jpg, there might be an alternate data stream, also called picture.jpg, containing the name of the author, a thumbnail of the image, or other information.
||For more information, see this Wikipedia entry.
|Wipe Cluster Tips
||A cluster tip is the last bit of a cluster not used by a file. Files usually take up more than one cluster. For example, if a file takes up 2.5 clusters, the last .5 cluster is the cluster tip. Since these cluster tips don't automatically get erased, they can contain remnants of file information.
|Wipe Free Space Drives
||If you select this option, CCleaner will also clean the free space available on selected drives for the Endpoint. Since Windows leaves information behind in the free space when it deletes files normally, the Wipe Free Space Drives option is more secure.
||This is only available for Endpoints, and not for Groups or Networks.
|Wipe MFT Free Space
||Windows keeps track of deleted files in an index called the MFT (Master File Table). Over time, it can become quite large. This option cleans the MFT free space.
|Only delete files in Windows Temp folders older than 24 hours
||CCleaner Network will leave any files created or modified in the last 24 hours in the Windows temporary folders.
||Some temporary files are needed by Windows (on a temporary basis), so this setting preserves them.