This document is only for those using the old PGP not yet transitioned to BitLocker
Securely delete files on Windows with Symantec Encryption Desktop
To securely delete and encrypt files on Windows, Wellesley College has used Symantec Encryption Desktop (PGP Desktop). The secure deletion feature works by overwriting files you want to delete with random data. It repeats this process three times, which makes the files unrecoverable. You can shred individual files or folders, or shred all free space on the computer that may contain data from previously deleted files or programs.
This method that ensures the deleted files cannot be accessed, even through the usage of data-recovery software.
For information on how to install PGP Desktop, click here
Warning
Once files (and folders) have been securely deleted, they CANNOT BE RECOVERED. When using PGP Shredder, be sure that the files you are deleting will no longer be needed.
Drag and drop the files/folders you want to shred onto the PGP Shredder icon. A confirmation dialog box is displayed, asking you to confirm that you want to shred (secure delete) the listed files and/or folders.
Click Yes. The files are securely deleted from your system.
To shred files in PGP Desktop
In the PGP Desktop main application window, select Tools > Shred Files. The Open dialog box is displayed.
Select the files on your system you want to shred, then click Open. A confirmation dialog box is displayed, asking you to confirm that you want to shred (secure delete) the listed files and/or folders.
Click Yes. The files are securely deleted from your system.
To shred files by right-clicking in Windows Explorer
In Windows Explorer, right-click files/folders you want to shred. A confirmation dialog box is displayed, asking you to confirm that you want to shred (secure delete) the listed files and/or folders.
Click Yes. The files are securely deleted from your system.
Note: The shred session can be lengthy, depending on such factors as the number of passes you specified, the speed of the processor, and how many other applications are running.
PGP Shredder does not delete the following items:
Windows system files or files that are read-only.
Note: Note that the Thumbs.db file, created when viewing thumbnail graphics in Windows Explorer, is a special case and can be shredded even though the file has the system attribute set.
WebDav or Sharepoint files. Files that can be deleted are local files and CIFS shared files.
Directories containing files that cannot be deleted.
Shred Free Space on disk
PGP Shred Free Space allows you to erase free disk space that could contain data from previously deleted files and programs. It is especially important to use the PGP Shred Free Space Assistant on Journaling file systems such as NTFS, as such file systems make a second copy of everything written to disk in a file system journal. This allows you to destroy sensitive files or folders completely.
To use the PGP Shred Free Space Assistant
Open PGP Desktop.
Select PGP Disk > PGP Shred Free Space. The Introduction screen of the PGP Shred Free Space Assistant is displayed.
Read the information, then click Next.
In the Shred drive field, select the disk or volume you want to shred and the number of passes you want PGP Shred Free Space to perform. While three passes with PGP Shred are sufficient to securely delete the data, you can specify up to 49 passes. The recommended guidelines for number of passes are:
3 passes for personal use.
10 passes for commercial use.
18 passes for military use.
26 passes for maximum security
Choose whether to shred internal NTFS data structures. This option is not available on all systems.
Caution: If the selected partition is not your boot partition, you can perform an intensive shred operation that overwrites internal NTFS data structures that may hold residual data. The partition will be completely filled during this process, and as such you should not use the disk for anything else while the free space shred operation is in progress.
Some of these structures are not generally considered free space on your drive, but the techniques employed by this option will cause them to be shredded. This option does not increase the risk of anything negative happening to your disk as a result of the shredding operation.
Click Next. The Perform Shred dialog box is displayed, containing statistical information about the drive or volume you selected.
Click Begin Shred.
After PGP Shred Free Space completes, click Next.
Click Finish.
WARNING
Files and folders deleted by PGP Shredder CANNOT BE RECOVERED. When using PGP Shredder, make sure the files you are deleting will no longer be needed. File recovery programs cannot recover data that is deleted by PGP Shredder.
PGP Shredder can not delete the following items:
- Files saved on networked file servers such as NTM or Vault.
- NOTE: If you copy a file from Vault to your computer's hard drive to work on and edit, after you copy it back to Vault and verify it was copied completely and correctly, you should shred the copy on your computer.
- NOTE: If you copy a file from Vault to your computer's hard drive to work on and edit, after you copy it back to Vault and verify it was copied completely and correctly, you should shred the copy on your computer.
- Windows system files or files that are read-only.
To shred files using the PGP Shredder icon on your Desktop
- Drag and drop the files/folders you want to shred onto the PGP Shredder icon on your Desktop.
- A confirmation dialog box is displayed, asking you to confirm that you want to shred (secure delete) the listed files and/or folders.
- Click Yes . The files are securely deleted from your system.
To shred files by right-clicking in Windows Explorer
- In Windows Explorer, right-click files/folders you want to shred and select PGP Desktop > Shred ...
- A confirmation dialog box is displayed, asking you to confirm that you want to shred (secure delete) the listed files and/or folders.
- Click Yes . The files are securely deleted from your system.
To shred files from the PGP Desktop application
- In the PGP Desktop main application window, select Tools > Shred Files . The Open dialog box is displayed.
- Select the files on your system you want to shred, then click Open . A confirmation dialog box is displayed, asking you to confirm that you want to shred (secure delete) the listed files and/or folders.
- Click Yes . The files are securely deleted from your system.
Shred all free space on your computer's hard drive
PGP Shred Free Space allows you to erase free disk space that could contain data from files and programs previously deleted by normal processes and were not shredded. This allows you to destroy sensitive files or folders completely.
- To use the PGP Shred Free Space Assistant
- Go to Start > All Programs > PGP > PGP Desktop.
- Select PGP Disk > PGP Shred Free Space. The Introduction screen of the PGP Shred Free Space Assistant is displayed.
- Read the information, then click Next.
- In the Shred drive field, select the disk or volume you want to shred and the number of passes you want PGP Shred Free Space to perform.
- While three passes with PGP Shred are sufficient to securely delete the data, you can specify up to 49 passes.
- Choose whether to shred internal NTFS data structures, then click Next. This option is not available on all systems, and typically is not necessary.
- The Perform Shred dialog box is displayed, containing statistical information about the drive or volume you selected.
- Click Begin Shred.
- After PGP Shred Free Space completes, click Next.
- Click Finish.