Secure file deletion on Windows
Deleting a file in Windows and emptying the recycle bin removes the pointer to the file, not the data itself. Until that area of the drive is reused, recovery software can often rebuild the file completely.
Why a deleted file is still there
The file system marks the space as available and moves on. The bytes stay where they were, along with the entry in the file table that describes them. That is exactly what file-recovery tools look for, and it is why a secure deletion step exists.
What secure deletion does differently
- The content of the file is overwritten before the entry is removed.
- The matching entry in the file table (MFT on NTFS, FAT on FAT32) is cleaned as well.
- Residual fragments left in free space from earlier deletions can be overwritten in the same pass.
Hard drives, SSDs and USB drives
On a mechanical hard drive, overwriting is direct and predictable. SSDs and USB flash drives manage their own blocks internally, so repeated overwrites are neither necessary nor kind to the hardware; the sensible approach is to adapt the method to the medium, which is what PrivaZer does when it detects the drive type. For a whole SSD, the manufacturer's secure-erase utility or full-disk encryption from the start remains the strongest option.
Erasing a specific file or folder
PrivaZer includes a shredder: select the file or folder, confirm, and its content is overwritten instead of simply unlinked. It is the step to take before selling a PC, returning a work laptop or passing on an external drive.
Frequently asked questions
Can a securely overwritten file be recovered?
Once the content and the file-table entry have been overwritten, standard recovery software no longer finds anything usable.
Is the recycle bin enough?
No. Emptying the recycle bin only removes the reference to the file.
Should I overwrite an SSD several times?
No. Multiple passes add wear without real benefit on flash storage. Adapting the method to the drive type is the better approach.
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