The Alternate data streams is available only on NTFS drives.
The NTFS file system provides applications the ability to create alternate data streams for each stored file/folder. Although these streams are not visible to the average users, they can be easily found on the disk even after the actual file that they belong to are deleted. The streams contain many kinds of sensitive information since they have the same format as normal files.
This option can be accessed from the Privacy Guard module -> Advanced -> Windows.
Checking the Alternate Data Streams option will option a dialog/box, where you need to click “Search for alternative data streams”, to detect files with alternate data streams. The scan will identify all such files on your computer. This will give you the possibility to select the files you wish to remove the ADS from. all alternate data streams attached to a file will be destroyed and cannot be restored. Erasing the alternate data stream may destroy the entire file. If you check Keep the main file if possible , the program will try to preserve the main file. Otherwise it will be deleted as well.