If a person deletes a file and then empties the trash or recycle bin that file is gone forever, right? This is a mistake that many people make when working with computers by assuming that data that has been purged from the recycle bin cannot be recovered when in fact, unless additional steps are taken that data can still be brought back to life. For some this is a good thing. Everyone has deleted a file that they wished they could get back. For others however, the ability to get the data back can be a serious security risk, especially when the computer is going to be sold or passed on to someone else. Unless the data on the hard drive is properly erased by a third party program, a resourceful hacker could recover bank account numbers and other financial or personal information. This article covers the methods used to permanently delete data from a computer hard drive.
What Happens When A File Is Deleted?
When a file is deleted or purged from the recycle bin on a computer what actually happens is that the file is renamed in a way that tells the operating system that the space the file once occupied is now available to be reused. The data remains intact until it is overwritten by a new file. Depending on the size of the hard drive and the way the computer is used this means that the file could remain there for a very long time. Until the data is overwritten it can still be recovered (in most cases). For very resourceful hackers and computer experts it is even possible to recover a file AFTER it has been overwritten. This is why defragmenting or simply writing a lot of new data to the drive may not be enough to securely remove the file.
How To Permanently Erase Data From A Hard Drive
In order to permanently prevent data from being recovered from a hard drive a special erasing software program must be used. There are many of these programs available, both from commercial vendors such as SecurErase and also as a freeware program called, simply enough, Eraser. Eraser comes highly recommended, and adds a right click menu option to Erase The Recycle Bin or if a hard drive is clicked, to Erase Unused Space. In doing so, the program overwrites each sector of unused space on the disc with random bits of information. Most erasing programs have different levels of sophistication, allowing the user to overwrite each bit of data dozens of times rendering it effectively impossible to recover.
Wiping an Entire Computer Before Selling It
Utilities such as the previously mentioned Eraser can also be used to create a Nuke Disc. This disc can be used to boot the computer and then completely wipe the entire hard disc removing any and all sensitive data prior to selling or donating the computer to a charity. Just be certain that all necessary data has been removed or backed up to another drive before starting the process.
Using an erasing program can provide peace of mind and added security for your important personal information. Remember to completely erase files rather than simply deleting them from the recycle bin of your computer.
