Practical Methods of Deleting, Restoring, Splitting and Encrypting Files

Every few years I replace my computer. There's nothing on the present system that I'm ashamed of, but the thought of a stranger browsing through the family pictures, saved to the hard drive of my cast-off, brings on a queasy feeling. It could be disastrous if the wrong person were to gain access to my, Internet filed, tax returns or the confidential files I downloaded from the office.

So how do I handle this? How can I keep confidential files safe, and how do I clean up my system when I replace the old computer?

There are various methods of handling these problems. This article concentrates on those available to the Windows operating system and to Ashampoo WinOptimizer .

WIPING A DRIVE

Let's start with sanitizing the cast-off system. If it's going to landfill, the most efficient method is old-school - rip out the hard drive and bust it up with a hammer. The gentler techniques described below are useful for computers being donated or sold.

Most computer systems include either restore disks or a restore partition on the hard drive. In the best case scenario, once the computer is started, an F-key selection will restore the unit to its original state. Every piece of data added to the computer, since it was purchased, will be gone.

Another useful option is formatting . Unfortunately, it is difficult to format the drive containing the operating system. Formatting of secondary drives, external drives, and flash drives is much easier. From the start menu , click computer . Then right-click the proper drive and select format . Generally speaking, flash drives are formatted as fat32 and hard drives as NTFS . I formatted an 8 GB flash drive to begin the first series of tests. A full format required one hour. I used the File Undeleter tool from Ashampoo's WinOptimizer in a futile attempt to recover the files.

I formatted a 297 GB external drive using the quick format option. File Undeleter attempted, unsuccessfully, to recover the files. A more sophisticated tool might have met with success.

DELETING FILES USING WINDOWS 7

At times sensitive files must be removed from the computer or drive. Will Windows get the job done?

The Windows delete function does not actually eliminate files. It removes the pointers to these files. Although not listed, they still exist. Of course, because the pointers are removed, protection against overwriting is no longer present. Over time other data will encroach and overwrite the deleted files. Also note that deleted files are copied to the recycle bin .

I utilized Ashampoo File Wiper to remove the contents of an 8 GB flash drive. Six test files consisting of two photographs, two Microsoft Word documents, and two installable files were copied to the drive. By right-clicking the containing directory, these new files were easily deleted.

I browsed the flash drive and determined that the freshly deleted files were no longer listed. Using File Undeleter , I searched the drive and restored the deleted files to their original state.

The test files were recopied to the flash drive. After deleting them with Windows, an additional photograph was copied to the drive. File Undeleter searched successfully for the deleted files. In this case, however, one photograph could not be restored to a usable condition. The second, although named correctly, had been replaced by the photo copied after the deletion process. The remaining test files restored correctly.

These tests proved that deleting a file, using Windows, does not actually delete the file. Over time, however, it will become overwritten.

DELETING FILES USING FILE WIPER

File Wiper is a tool found in Ashampoo WinOptimizer. It can be utilized to wipe anything - from a single file, to an entire drive.

This software contains four methods of deleting files:

• Fast (One write iteration; Only recommended for SSD Hard Drives and USB sticks.)
• Default (Three write iterations; Data could potentially be restored in a laboratory on a normal hard drive.)
• DoD 5220.22-M (Seven write iterations; Extremely difficult to restore.)
• Gutmann Method (Thirty-Five write iterations; Impossisble to restore)

The definition of iteration is to repeat. My understanding is that the Fast method will overwrite the file once. The Gutmann method overwrites the file 35 times.

A test was conducted to determine the speed of this process. My six test files occupy 163 MB of space. These files were inserted into a directory located on the hard drive, and into a directory located on the flash drive. The deletion process was timed.

• Fast required three seconds. (Hard Drive)
• Default required nine seconds. (Hard Drive)
• DoD 5220.22M required seventeen seconds. (Hard Drive)
• Gutmann Method required two minutes, thirty-five seconds. (Hard Drive)
• Gutmann Method required four minutes (Flash Drive)

A second test was conducted to evaluate how well the deletion process works. The results are incomplete due to lack of access to the sophisticated software and equipment necessary to perform a comprehensive test. The recovery software selected, File Undeleter, is a basic program designed to recover files deleted by Windows.

It required twenty-seven minutes to search the 8 GB flash drive. Among the 1800 files, File Undeleter discovered, it found my six test files. The software restored the files but attempts to view the pictures, open the word processing files, and run the installable programs, proved fruitless. Even files deleted using the Fast method were corrupted.

FILE ENCRYPTION

File Encrypter and Decrypter are tools available in WinOptimizer. This program will encrypt one file at a time, and requires a 4 to 16 character password. Options allow deletion of the original file and the generation of a self-decrypting EXE file.

The encryption process is quick; even my large installable programs were processed within seconds. When encrypting the files I selected the self-decrypting option. Simply double-clicking the previously encrypted file brought up a request for the password. Once the password was entered, the file speedily decrypted and could be saved in a specific location.

If you use WinOptimizer to decrypt a self-decrypting file, it will report that the file appears not to be encrypted. It is encrypted but a file of this type is meant to be opened independently of WinOptimizer.

I suspect tools are available to crack these files. A cautious individual might consider encrypting the encrypted file as a further safeguard.

There is one potential area of weakness to be examined. While the encrypted file is reasonably protected, the original is not. Unless its location is secure you should use a tool such as File Wiper to destroy the original. File Encrypter's option to delete the original file works in the same manner as Windows delete. The files can be easily recovered.

SPLITTING AND MERGING FILES

Sometimes a file cannot fit on the media it is being saved to. File Splitter and Joiner, part of WinOptimizer, is used to split a file into several sections. I chose a 132 kB file and selected the option to split it into files small enough to fit onto a floppy. Seconds later 96 tiny files were created. I only own one floppy - a boot disk for Windows Millennium - so I used File Splitter and Joiner to rejoin these files. The result, an installation file for Ashampoo Photo Commander, proved uncorrupted.

FINAL CONCLUSION

Under most circumstances, the delete feature included in the Windows operating system is all that is required. Flash drives and hard drives that do not contain the operating system can be easily wiped by formatting. Unless security is paramount, a quick format is sufficient.

Sensitive files can be securely wiped using the file deletion features of Ashampoo WinOptimizer. Unless extremely large files are being deleted, it is practical to use the Gutmann method.

File encryption is another feature of WinOptimizer. After encryption, ensure that any unprotected originals are securely wiped.

WinOptimizer features a tool designed to split and merge files. In these days of 32 GB flash drives it may not be required often, but is nice to have available.