A computer eraser, (also computer cleaner, or privacy cleaner), is software that removes traces of a user’s activities to help maintain privacy against casual snoops that might subsequently use the machine. The software can wipe a variety of records with a single click of a button, is fast, convenient and in many cases, free.
Many of the features built into operating systems and software that make it so convenient to use, can also make it easy for a third party to “spy” on your computer session without your knowledge. Long after you’ve left the computer, someone can easily see what documents you called up, images or movies viewed, and more. Your searches and surfing habits can also be ascertained with ease. A subsequent user might even gain access to information entered into forms, sometimes unintentionally.
Most word processors and other office programs maintain lists of recently viewed files so that a user can bring up something he or she has recently worked on without searching for it. A subsequent user can then easily see what was opened prior. This is true of media players and graphic programs as well. Even the Run, Search and Find functions keep records of previous entries, showing these parameters when the function is next accessed.
Web browsers also reveal much about previous sessions, providing a computer eraser doesn’t help them forget. The URL window which displays the current website address is commonly augmented with a drop-down box of previously visited sites and will auto-fill the address window based on the first few keystrokes entered into the field.
If set to do so, a browser can also remember usernames and passwords for registered websites, using a cookie to auto-fill the fields when the site is re-visited. This can allow access to a personal account, perhaps to highly sensitive banking or credit card information. Cookies in general reveal where you have been online. Nearly every site you visit will generate multiple cookies, some of which will persist on the hard drive and can be viewed with any text editor to see the website addresses that generated them.
Web browsers also set aside hard disk space to use as cache, or a storage locker for images of frequently viewed websites. By keeping these Web pages handy, the browser can pull the site up quicker on subsequent visits, improving performance. A computer eraser will also address this.
Browsers do have privacy settings that are user configurable, but they can fall short of doing a good job. For example, Microsoft Internet Explorer will wipe its history, cache, cookies and temporary files, but it does not wipe the index.dat files, which archive links to this information and more. These files are not available to delete inside Windows because they are always in use and locked.
A computer eraser tracks down all of these footprints and and wipes them, leaving the computer looking as if you were never on it. It will do a better job and be more convenient than built-in tools, and will also be configurable to allow you to optionally spare certain files, such as specific useful cookies. Depending on the files being wiped, the tool might require a reboot so that it can delete locked files. Computer erasers are available as freeware and shareware, and as portable programs that run from a USB flash drive so that they do not have to be installed. Read reviews and ratings to find a good program.
Although a computer eraser does a nice job of guarding against casual spying, it is not a forensic tool and should not be relied upon to mask criminal or illegal activity. Swap or paging files and other more obscure traces of activities might provide other sources of information to law enforcement or administrators. Server records will also map illegal activity back to a specific network or computer, complete with date and time stamp. For routine privacy, however, a computer eraser is a handy utility.