1. Securely Deleting Files on your Windows Computer – SDelete
As a part of the Data Cleanup initiative here at Georgia Tech, it is important to remember to not only securely dispose of paper files (e.g. shredding), but also to securely dispose of electronic copies of the files. This can be done in one of two ways. You can either securely delete files that you would normally erase when emptying the recycle bin, or you can “wipe” the free space on your hard drive. This is a process of over-writing the space your files used to exist in so that they are not recoverable. One of the tools that you can use to accomplish this is S-Delete by Microsoft (formerly Sys Internals). S-Delete is a command line (CLI) application that can securely erase files and wipe free space on your hard drive. Please read the directions carefully before beginning! Once you have erased a file using S-Delete, you cannot recover it! It is highly recommended that you back up your system and any sensitive files before beginning.
2. S-Delete for File Deletions
The current version of SDelete is 1.51. The website may be found at: http://www.microsoft.com/technet/sysinternals/Security/SDelete.mspx 1. To begin, download SDelete to your computer from: http://download.sysinternals.com/Files/SDelete.zip 2. Unzip the contents to your hard drive (e.g. create a new folder called C:\SDelete and put the contents in this folder).
© Georgia Institute of Technology
Page 1
Georgia Institute of Technology S-Delete How To
Rev.1.0
3. Next, let’s create a directory in the C:\SDelete directory called “delete.” You can use this directory to store all your files you are going to delete using sdelete. To do this, go to File -> New -> Folder. Then, name the file “delete.”
© Georgia Institute of Technology
Page 2
Georgia Institute of Technology S-Delete How To
Rev.1.0
4. Before continuing, take the time to move the files you wish to delete to the folder C:\SDelete\delete. Explorer would be a good option to do this. For our purposes, I have moved a document called test.doc to the directory. 5. Now, open a Command Prompt by going to Start -> Run and typing in “cmd”.
© Georgia Institute of Technology
Page 3
Georgia Institute of Technology S-Delete How To
Rev.1.0
6. Now that you have a Command Prompt, you will need to go to the directory that contains the SDelete executable. Do this by typing:
© Georgia Institute of Technology
Page 4
Georgia Institute of Technology S-Delete How To
Rev.1.0
cd C:\SDelete
7. To erase a file or directory securely, you will need to run the command: sdelete For example, to erase our example file in C:\SDelete\delete, we would run the command: sdelete delete\test.doc When you run this command, you will be asked to agree to the License Terms (click Agree to continue) and the delete will occur.
© Georgia Institute of Technology
Page 5
Georgia Institute of Technology S-Delete How To
Rev.1.0
8. In most cases 1 pass will be enough. If you wish to run more than one pass, run the command with more than one pass sdelete –p 7
3. S-Delete for Wiping Free Space on a Hard Drive
1. To wipe the free space on your hard drive and remove any traces of formerly deleted materials, you would use a similar command. From the SDelete folder, run the following command from the Command Prompt: sdelete –z c:
If you wish to make more than 1 pass, run the command with a –p option and the number of passes you wish to make. For example, if I wanted to make 4 passes over the free space, I would run: sdelete –p 4 –z c: This will take time, so it is best to do this in the evening and let the process run overnight.
© Georgia Institute of Technology
Page 6