Data stored on a computer can be precious. In most cases, it’s more precious than the hardware itself. Not only that, but data can also be valuable. Think of commercial software, proprietary applications, and top-secret documents.
For this purpose, sometimes you will need to delete ALL data on a computer. This should be done in the following instances:
- You are selling the computer on the used computer market
- You will be donating the computer to charity
- You are upgrading hard drives and you are disposing (or giving away) your old hard drive.
- Other instances in which you want to keep the data on a hard drive safe and secret.
System recovery. The first means of deleting data on a computer is if it came with a system recovery disk. This will mean the computer will be reset to factory settings, so all information you have saved, all work you have done, and any modifications will revert to original, as far as software is concerned. Look for your recovery CD or DVD from your computer’s packaging. In some cases, this recovery data will be stored on a partition on the hard drive. Try rebooting your computer, and look for a message saying Press XX to enter system recovery (where XX is usually a Function key).
Formatting. The next easiest way to delete all data on a computer is through formatting. This is a crude method, and does not actually give you a 100% assurance that all your data will be deleted. You can wipe out your hard drive by using a bootable DVD or CD or a USB drive. The most accessible way you can get a bootable media would be through your Windows installation disc. Simply go through a new installation process and delete all existing installations. When prompted, choose to format the hard drive where Windows will be installed. If you have an option, don’t use the “quick” format method.
Using a quick format will simply delete the file allocation table on your hard drive. This way, data still resides on the disc, but will no longer be mapped like it was originally. If this is the case, then it is still possible to recover data from your hard drive. This is not ideal if you are worried about potential theft of your identity or your work that was previously stored on the hard drive. These can be recovered using an undelete program.
Boot and Nuke. Because simple formatting will leave your computer data susceptible to recovery programs, it’s best to use applications specifically meant to delete data from the lowest levels of the hard drive. You can download a simple application called Darik’s Boot and Nuke (from www.dban.org). Boot and Nuke is meant to wipe out the contents of magnetic media completely, and prevents any forensic analysis from being done on a disc. Darik’s Boot and Nuke can be burned or copied onto a removable media, which includes floppy disks, recordable CD or DVD, or a flash drive.
Boot and Nuke’s readme.txt file provides several instructions on how you can delete data. The easiest is by using the autonuke command. Simply boot up with Boot and Nuke, and at the command prompt, type autonuke. This will automatically delete all data on all drives on the computer.
Data deletion is a responsible means of handling your computer data when you will be selling, donating, recycling or disposing of your computer. Protect yourself, your business and your family by preventing important and potentially sensitive information from falling into the wrong hands.