Do you know how common it is to buy a secondhand hard drive from ebay or at a car boot sale only to find easily retrievable personal data left in error by the previous owner.
“That would never happen to me,” I hear you say. “I’ll delete everything first. I’ll even re-format the drive before I get rid of it.” Not necessarily the right answer!
Simply deleting a file doesn’t actually remove it from your drive, even when you empty the recycle bin. The file content remains on the disk until new data is physically written over it. All that happens with ‘deleted’ files, is that the space they occupy is marked as effectively free or unused space on your drive. The same is basically true even when you reformat the drive.
So what is the real answer. Well, using data wiping software is a good starting point. One of the best of these is Eraser, a free Windows utility that allows you to securely erase files, folders and even the unused space on your hard disk. It wipes the data by writing pseudo-random data over the selected file(s) you want to securely delete any number of times you wish.
The more times you overwrite the space, the more unlikely it is for anybody to be able to recover the original data. The number of wipes can range from once, through the US Department of Defense (DOD) recommendations of either 3 or 7 times, to the belt and braces Gutmann recommendation of 35 times! The more times Eraser overwrites or wipes, the more secure the deletion, but remember the longer the overall process will take and potentially the more wear you put on your hard drive. The secret is to match the number of wipes you employ to the sensitivity of the data you are erasing.
Add Eraser to your list of valuable programs and give it a try. You can download the latest version at www.eraser.heidi.ie