When it comes retiring PCs at the office or at home, regardless of whether their final destination is a tip or to be sold to recover an investment, it goes without saying that a computer's drives need to be wiped. For the corporate environment, you're going to want to make sure no sensitive data is left behind however benign, and for the home you don't want leave any trace of personal details or credit card transactions that could be picked up and used in identify theft.
When a PC leaves your care it's always good practice to ensure data has been securely removed. And it's not enough to merely delete data or re-format a partition--the 1s and 0s that make up the data are still there, and easily recoverable with the right tools.
It’s why there are a plethora of disk wiping tools available and -- the bean counters in accounts will be happy with this--you don't need to purchase expensive software to do it. There are plenty of free tools that will do the job for you, but as you’ll see below, there are a number of paid products too.
Wiping software will usually support two different methods -- filesystem-based, and disk-based. Naturally the later wipes an entire device, and generally this is the preferred method if you want to ensure data has been cleaned, even if a program is effective at overwriting a file with multiple passes, a copy of the file or its data may reside elsewhere such as in the swapfile, journaled data, or temporary files. However, it all depends on what your security needs are.
In this review we've rounded up some of the more popular tools, as well as some you've probably never heard of, to see what's available and how they can work for you.
CCleaner is a popular 'crap' cleaner tool for removing temporary files, browser caches, log files and other junk from a system, a job it actually does quite well. However, it also includes a 'Drive Wiper' under its Tools section, which is capable of doing free-space or whole disk wipes using a selection of four different methods, from the simple 1-pass overwrite to a Gutmann 35-pass process. It's not as fully featured as some of the other products listed here, but it does the job well and it's free.
Slimware Slimcleaner Shredder—www.slimwareutilities.com/slimcleaner.php
Slimcleaner is Slimware's equivalent of CCleaner, but it also comes with a wiping tool called Shredder. It also sports a selection of wipes, from 1–pass up to 35-pass Gutmann modes (see sidebox 'Grading Secure Wipes') and allows you to add files and folders from multiple sources to create a wiping list before clicking the 'Shred' button. Although it doesn't explicitly state it can wipe whole drives, selecting 'Folder' and clicking on the root will achieve this. However, this is not the same as a full disk wipe, file system structures will still persist. Not a bad product and, again, free.