Although people routinely think about viruses, trojans and spyware, seldom do people think about how to properly erase data from their hard drive. Some people simply drag files to the Recycle bin and later throw them out. But there are plenty of places Windows stores data that aren't apparent such as your internet history. The data in these places may also be sensitive such as passwords or account data and require a secure data removal program like Eraser.

Deleted Files in Windows Remain

When you think about protecting data, most people think of the files they can see in folders. As example, the marketing plan they wrote in Microsoft Word. To get rid of this file, people will drag the file to the Recycle bin. Out of sight, out of mind, out of reach not really.

Although you deleted the file, the data is still on your computer. The file's first letter is changed and references are deleted. If someone used a disk editor, they could see your deleted marketing plans. Some people take a step further and defrag their hard drive so the marketing plan data gets overwritten.

The above steps help, but they're simple ones and only address the files you decide to delete. The bigger issue is the unknown which is where Windows comes into play. Sensitive data from that marketing plan, or any other file, can be found in temp files, cache, swap files, page files and slack space.

While you didn't explicitly request Windows to place parts of your files into any of these areas, it does so in its normal processing. Most of this processing is done as a convenience to the user. When your machine needs more memory to handle large files, display web pages, or to print documents, Windows may leave sensitive data fragments behind. The problem is finding out if there is sensitive data in these areas.

Scrubbing the Data Clean

We prefer to take a practical approach and use a free disk scrubbing program called Eraser. The reason we say practical, is that to ensure any data is 100% deleted calls for physically destroying media. Even then, you have to destroy the media correctly. As example, most four year olds can destroy a hard drive, but not to Dept of Defense standards.

Using Eraser, you can delete sensitive data and files using various data overwriting methods and still keep your hard drive. This makes the program ideal for regular use or when you donate your computer. In addition, to doing data scrubbing on an On-demand basis, you can also create scheduled tasks. As example, you could tell the program to scrub unused space on Drive C: every Friday at 10:00 PM.

Eraser allows you to act on data in three ways as numbered in the screen below. The first way is to erase the data on the unused space on a drive. This would include data in slack space and unallocated space. When Windows saves files, it uses file clusters which are units of a fixed size. However, a file may not fill the cluster. The room left over is called slack space. When you delete a file, you're allowing Windows to overwrite that area with new content. But, if the new file needs less cluster space, a part of the previous file, such as your deleted marketing file, is not overwritten and still remains.

The second way to delete or scrub data is by folder. This is where you can select which folder and subfolders to scrub. This is also where you need to verify the content should be deleted. As example, you might select your Cookies folder, but you may find later that you wanted some cookies to personalized sites such as My Yahoo! The program is designed to securely delete files so if you make a mistake you're probably going to need a forensics expert with some fancy hardware. The same warning applies if you use the third way to delete specific files.

The program also allows you to drag and drop files and folders onto the program's task area. Or, you can right-click a file or folder to delete it as well.

The program includes many preferences. These dialogs are where you can choose which data overwrite method to use. By default, the program includes 4 overwriting pattern methods including 2 which are US DoD standards. The program also allows you to create your own erasing methods.

We found the program easy to use, yet powerful. But, we also know some people have expressed anxiety over deleting files. To get acquainted with the features, you might want to test the program by creating a task to delete a few selected files.

If you have questions or want more information, the author has included a help file. This file includes step by step instructions on some common tasks such as deleting cookies, index.dat and email files. In addition, there is a comprehensive Frequently Asked Questions section on the website.

• URL: http://www.heidi.ie/eraser/
• Version Reviewed: 5.7
• Cost: Free