Secure Your Hard Drive: Wipe It Clean

When some people decide it is time to get a new computer they decide to not throw it away, to them it still has value. So, they decide to sell it or donate it—hard drive and all. The hard drive is full of important, and most of the time private and confidential, data and information. Before you put it up on eBay or give it to your church, you must be sure all the hard drive data is gone.

Erasing a drive or reformatting a hard drive is just not enough. Again, most people believe that reformatting a drive completely gets rid of all data not so. It is the same with deleting files. When a file is deleted in Windows, it just removes the shortcuts to the related file. This only makes that file invisible to the user. Deleted files are still on the hard drive and disk recovery software that is easily available, and sometimes for free, can allow someone to bring that file back. So, a deleted file is not a file gone forever. It is just a file that needs a little resuscitation.

Formatting the hard drive is a bit more secure than simply erasing the files. Formatting a disk does not erase the data on the disk, only the address tables. It makes it much more difficult to recover the files. However, a computer specialist would be able to recover most or all the data that was on the disk before the reformat. Those who accidentally reformat a hard disk can recover most or all the data that was on the disk is a good thing. But if you're preparing a system for retirement to charity or sale, this obviously makes you more vulnerable to data theft.

The most secure way to completely clean a disk is a process called disk wiping. Disk wiping is not only used in reference to hard drives but any storage device such as CDs, RAIDs, thumb drives and others. Disk wiping is a very secure method of ensuring that all data, including personal and confidential information is irrecoverably deleted before recycling or donating the equipment. Because previously stored data can be brought back with the right software, the disk wiping process will actually overwrite your entire hard drive with data several times. Once you format the wiped drive it will be all but impossible to retrieve any previous data.

While disk wiping algorithms differ from product to product, they all will generally write the entire disk with a number (zero or one), then a reformat will be needed. The more times the disk is overwritten and formatted the more secure the disk wipe is, but the trade-off is the extra time to perform additional rewrites. Disk wipe applications will typically overwrite the master boot record, partition table, and every sector of the hard drive. To wipe a disk you just need to search for it online and there will be many applications available both for sale and for free.