Hard Disk Scrubber v3.4 Welcome to Summit Computer Networks' latest release of the Hard Disk Scrubber. This release is at least 2X faster than the 2.x versions, and supports larger drives, and is Vista and Windows 7 UAC compliant. This version will not run on earlier Windows platforms such as Windows 95, 98, or Windows ME. This build requires Windows 2000 or newer.

Once you have installed the Hard Disk Scrubber you can run it by clicking on the icon in the Start menu or on the desktop. If you are running Windows Vista you will see a message "An Unidentified Program Wants Access To Your Computer" and you will need to select "Allow" in order to run this utility. This utility requires Admin Access to the system in order for it to function properly. Once you have opened up the Hard Disk Scrubber you will see the main screen pictured below.

There are 2 basic parts to the Hard Disk Scrubber. The first is the Hard Disk Free Space Scrubbing option, and the second is File Scrubbing (or File Shredding). When you scrub a hard disks free space you overwrite unused space that may have been previously in use by other files. Files that you deleted using the recycle bin, or through Windows can easily be recovered or undeleted using the proper utilities. The hard disk scrubber will ensure that these utilities can no longer restore files that were previously deleted on your system. File scrubbing is a way to securely delete existing files on your computer. If you have files that you want to delete permanently then you can use this utility to get rid of the files so that they can no longer be accessed. Using this utility will ensure that undelete utilities cannot access the data that was deleted using this program. File scrubbing can be used during your every day deleting of sensitive documents and files, while disk scrubbing can be used less often. You may scrub the disk if you used other means of deleting sensitive files. Also if you are getting rid of your computer you should scrub the free space. Even if you have formatted the drive and re-installed the OS, old data can still be recovered!! Make sure that you overwrite your free space before getting rid of any computer, otherwise you leave yourself open to identity theft and other problems resulting from your old data winding up in the hands of an unauthorized party.

File Scrubbing: To scrub files, you must begin by adding files or folder contents to the list found on the right-hand side of the program's main window. Use the Add Files and Add Folder buttons for this purpose. When using the Add Files button, you can select one file at a time, or select multiple files. The Add Folder button will add all of the files to the list that are found in a given folder. Subfolders and their contents will not be added to the list when using the Add Folder button. To remove a file from the list, double-click on the file that you want to remove, or use the Clear List button to completely empty the list. Once you have the list filled with the files that you want to delete, select the scrub type on the bottom-left side of the window. These types will determine how many times and what ways that the files in the list will be overwritten before they are deleted. These types are described in detail later in this document. Next you should check the Rename Files box if you want the Hard Disk Scrubber to first rename the files before removing them from your system. This is one more security step that can be taken to deter any would be snoops.

If you are using any patterns that have verify enabled on them, you can also check the Halt on Verify Error box. This will cause all file operations to cease immediately on the first verify error. If the box is not checked, the scrubber will simply continue on and notify you of the errors at the end of the process. Once you have selected your options, click on the Scrub Files button to begin the process. The amount of time that the process takes to complete will depend on the Scrub Type, Priority Level, Number of files, Size of files, and the speed of your computer. Obviously the greater number of overwrites (passes) that you choose the longer the process will take. To stop or interrupt the scrub process click the Scrub Files (Stop Scrub) button once again. The program will finish the current file task, and then stop.

Drive Scrubbing: To scrub a drive, you will first need to select the drive to be scrubbed in the drop-down. After you select the drive, choose the Scrub Type, and then click on the Scrub Drive button. Drive Scrubbing can take a very long time depending on the amount of free space that is on your drive, processor speed, and the Scrub Type selected. To stop or interrupt the scrub process click the Scrub Drive (Stop Scrub) button once again. The program will finish the current task and then stop. If you enable the Log File for disk scrubbing (there is no log file creation for file scrubbing), the Hard Disk Scrubber will log any pertinent actions as they occur to the log file which will be located in the root folder of the currently selected drive. If you place a check in the Shutdown PC on Completion box, the hard disk scrubber will shut down the PC once all passes have been completed. If you use this option, it is recommended to also use logging, so that you may examine the scrub results at a later time.

Time Estimation: The Hard Disk Scrubber will do very rough time estimating for the process to complete in real-time while it is running a job. This is done by taking samples of how many bytes per second are being written during a given interval, and then calculating the remaining time based upon the bytes that remain. Since Windows or other applications will also be sharing these time-slices, as well as some operations are faster than others, the time will tend to fluctuate depending on what is taking place on the PC at that moment. Again, this is only a very rough estimate, and is not to be considered an exact amount.

Scrub Types: The Hard Disk Scrubber v3 offers new scrub types in addition to Normal, and Heavy that were found in earlier versions of the software. A description of each of these types follows. Each "Scrub Type" is a collection of "Scrub Patterns". The Hard Disk Scrubber offers 6 different scrub patterns in all. Each pattern is a 512K block of bit data. This data is what is used to overwrite the private data that you are permanently destroying.       

All Zeros -- This pattern is a block of all binary 0's All Ones -- This pattern is a block of all binary 1's Random Pattern -- This pattern is a randomly generated block. Checkerboard Beginning with Zero -- This is a 01010101 block pattern. Checkerboard Beginning with One -- This is a 10101010 block pattern. User String -- This is a block comprised of a repeated user defined string. Verified Type -- This is any of the above patterns with a read verification pass.

The above patterns are then arranged into passes to create the different Scrub Types. The Scrub Types are defined below.     

Normal -- Single Pass using Random Pattern Heavy -- Three passes, using Zeros, then Ones, then Random. Super -- Five passes, using Zeros, Ones, Checkerboard Beginning with Zero, Checkerboard Beginning with One, then Random. Ultra -- 9 Passes as prescribed by the DoD standard for destruction of computer data (overwrite, overwrite with 1's compliment, overwrite random, then verify. These 4 steps, repeated 3 times.) Custom -- User-definable scrub type.

Priority: The Priority controls how much priority the scrubber is given in comparison to other applications and processes running on the PC at the same time. The higher the priority set in the scrubber, the more time that it gets from Windows and the slower your PC will seem to run, for other aps and tasks. If you are running the scrubber exclusively, then you should use a higher level, to help it run a little faster. If you are scrubbing while using your PC for other tasks as well, then a lower priority should be used to help your PC run smoother. When a lower priority is set, the scrubber can run just as fast (when nothing else is running) as it does using a high priority, but other aps will slow down the scrubber so that they may operate more smoothly when the scrubber is in a lower priority mode.

Advanced Features: With Hard Disk Scrubber v3 you can create your own complex Scrub Types simply by editing the user-definable scrub pattern. Click on the "Edit" button located next to the Custom (user definable pattern) scrub-type selection. This will open the custom pattern editor and you will see a screen like the one below.

The lower field is where you can select the pattern numbers to be used in your custom scrub configuration. This field will contain a string of numbers that are separated by commas with the range from 1 to 6 and 11 to 16. Each number represents which pattern will be used in subsequent passes. If you had a definition like the one below; 4,5,1,2,3,4,5,3,6 You would end up with a 9-pass scrub (one pass for each number separated by commas) using the following patterns: Checkerboard Beginning with Zero, Checkerboard Beginning with One, All Zeros, All Ones, Random, Checkerboard Beginning with Zero, Checkerboard Beginning with One, Random, and User String. By adding 10 to the basic pattern numbers of 1 through 6, you get the same pattern but with a verification pass. Patterns: 1 = Write All Zeros 2 = Write All Ones

3 = Random Data 4 = Checkerboard (starting with 0, eg. 01010101) 5 = Checkerboard (starting with 1, eg. 10101010) 6 = User String (set using editor) 11 = Same as Pattern 1, with verify pass 12 = Same as Pattern 2, with verify pass 13 = Same as Pattern 3, with verify pass 14 = Same as Pattern 4, with verify pass 15 = Same as Pattern 5, with verify pass 16 = Same as Pattern 6, with verify pass The User String can be any single-line string of text of your choosing. This string is set with the top edit field on the editor screen. This is my custom user string... The above would cause a file to be overwritten with data something like: This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... This is my custom user string... In order to use the Custom Text you must put the number 6 (or 16) somewhere in the Pattern #s list in your custom configuration.

FAQs: Q. Where did my free space go?? A. You may have interrupted the scrub process or it was not able to remove the files once the process completed. Do one of two things. Select a different drive in the drive drop-down, and then re-select the drive you scrubbed, or exit the program and re-open it. You should see a message like the one below.

Answer Yes to restore your free space. You may also manually remove the files as well. The Hard Disk Scrubber places files in a folder called SCRUBWRK on whatever drive that it was scrubbing. Simply delete the SCRUBWRK folder.

Q. How long does it take to scrub the free space on my hard drive? A. This depends on many factors. Obviously the amount of free space that the drive has, the speed of the drive, the speed of the processor, and the number of other processes running, and the current priority of the hard disk scrubber all play a role. Anti-virus programs can also slow the process drastically in some cases because they are looking at every thing that is read and written from the system's disk drives.

Disclaimer: This program is Freeware and is distributed AS-IS. The author(s) and/or distributor(s) cannot be held liable for any damages caused either directly or indirectly by the use of this program. Use of this program is at YOUR OWN RISK! This program is ©2010 by Summit Computer Networks, Inc. Visit our website at www.summitcn.com for the latest versions of this software as well as other useful utilities.