Secure Erase of Hard Drive Before Donation or Disposal — Why and How

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Summary

An old hard drive typically contains many old deleted files that can be recovered fairly easily. For this reason, it is important to make sure drives are securely erased before donating them or discarding them. The rest of this document provides instructions for the steps you might take to erase an old drive.

Disclaimer: These instructions are offered as a courtesy, and every effort has been made to ensure they are as complete, accurate, and clear as possible. However, there is always some risk associated with performing tasks on your own, so this document can’t guarantee nothing will go wrong in the process. Possible problems might include damage to a computer that is being disassembled, or getting injured on sharp pieces while taking a computer apart. Mistakenly erasing the wrong drive is also a potential problem.

Drive Destruction

To save time and money, some people will smash an old drive with a hammer, or they may drill through the drive multiple times to make it unusable and unreadable. However, this results in broken components that need to be thrown into the waste stream, and due to environmental concerns, generally people don’t want old parts going into landfill.

Alternative Erase Method

If your computer is still functioning, you can get a fairly reliable erase procedure accomplished by reinstalling Windows (or macOS for Apple computers) and then using a utility program to erase the remaining unused space on the hard drive to remove any recoverable remnants of previously deleted files. Most people would feel comfortable with this approach. If your computer is not functioning, then the procedure described below would be necessary.

STEP #1 — Remove Your Drive

Every computer is different so it’s not possible to offer detailed instructions for your particular model.

• DESKTOP — With desktop computers that have a large case, it may be easier to access the hard drive. There may be one or two screws to remove the cover of the computer, and then one or a few screws to be removed to get the drive out. However, some desktop computers have small cases or are an all-in-one design that make them very difficult to open. You may want to find a YouTube video that shows the process for your computer or something similar.
• LAPTOP — Laptop computers are generally much more difficult to open. Here are a few of the possible designs you may encounter.
  • SLIM LAPTOP — With new, slim and very portable laptops, there may be many small screws on the bottom of the case and some may be hidden under rubber feet that are stuck on to cover them up. You will need a video or visual guide for your specific model. Once the screws are removed, then the bottom cover can be removed, but this may be very difficult and require a special tool called a spudger. [View Samples] A spudger may be plastic or metal and may have a flat end or round end. It’s designed to separate pieces. When a laptop cover is removed, you may hear a breaking sound which are the plastic clip retainers in the computer breaking free. Sometimes they are damaged, but other times they are just noisy. If you want to replace a defective hard drive and then continue using the old laptop, you will need to be extra careful. If you only want to remove the drive and are not concerned about damage to the computer, then you need to be less careful about damaging the cover.
  • BUILT-IN DRIVE — Some laptop computers will have a hard drive that is built-in on the main logic board (the motherboard). These are solid-state chip-based drives that can’t be removed. If the computer is still running, you could reinstall Windows using the recovery mode, and then use a drive erasing utility to erase all unused drive space to delete any remnants of old deleted files.
  • EXTERNAL COVER — Some laptop computers will have a panel that offers easy external access to your drive by removing one or maybe a few screws. These computers have an external access panel you can remove to access the drive.

STEP #2 — Use an Adapter, Dock, or Enclosure

Use an adapter cable, drive dock, or drive enclosure with a USB cable to connect the drive to your new computer, or a borrowed computer.

• ADAPTER — A drive adapter will work with most modern drives made within the past 5-7 years or perhaps older. The adapter cable has a combined power data plug at one end that fits on the old hard drive, and a fast USB 3 plug on the other end. An advantage of the adapter cable is that it fits on small laptop drives as well as larger desktop drives. [View or Purchase]
• DOCK — A drive dock is a helpful device that holds drives temporarily for reading them. These may plug into a wall outlet for external power so as not to place an excessive power drain on the USB port. [View or Purchase]
• ENCLOSURE — A drive enclosure is typically sized to fit either a laptop drive (2.5-inch) or a desktop drive (3.5-inch). If you use an enclosure for light periodic use it should be okay. However, extended erasing processes may require that you not close the cover of the enclosure to avoid overheating. Some drive enclosures have a hinged lid to make it easy for opening and keeping the drive cool. [Laptop Drive Enclosure or Desktop Drive Enclosure] Note that the links here are for searches on Amazon that may include items other than what is desired.

COOLING IMPORTANCE — With any of the above USB drive devices you will want to have a cooling fan to keep the drive from overheating. This is more important for an erasing process because the drive will be continually in sustained use for an extended period of time. When installed in a computer, hard drives benefit from the computer’s thermal cooling. However, when not installed in a computer, the drive must have supplemental cooling. Fans that are USB-powered can be a good choice because they are generally small, inexpensive, and low power. [View Samples or Buy]

Secure Drive Erasing Software Utility Apps

There are a variety of software programs that can securely erase hard drives. Apple Mac computers come with a program called Disk Utility that can securely erase drives. For Windows users, an easy and free solution is CCleaner software. These instructions assume you are on a Windows computer and will use CCleaner to erase your external drive.

1. DOWNLOAD — Go to the CCleaner.com website and download the CCleaner Free software. Do not download the free trial of the Pro version. Instead, scroll down on web page and under the CCleaner Free column of features click on the green “Download” button. This will place the installation file for the software in your downloads folder. Be sure that you don’t accidentally download the CCleaner browser. It is not necessary and will just be additional software you don’t need right now.
2. INSTALL — The downloaded file may show up in your browser in the lower left or top right area of your browser window. If not, in your downloads folder look for a recently downloaded file named ccsetup586.exe or something similar to that. This is the CCleaner installation software. Open the file to begin the installation.
   1. From the initial CCleaner setup screen, click on the small customize link under the Install button and use the following selections clicking the checkbox to select yes, and remove the checkmark from the checkbox to indicate no.
      • YES – Add Desktop Shortcut
      • YES – Add Start Menu Shortcuts
      • NO – Do not Add ‘Run CCleaner’ option to Recycle Bin context menu.
      • NO – Do not Add ‘Open CCleaner’ option to Recycle Bin context menu.
      • NO – Do not Enable Intelligent Cookie Scan
   2. When done with the above selections, click the blue “Install” button.
   3. Once the setup has completed you should see a message that states “Setup Completed.” Remove the checkmark next to “View release notes.” Then, click the button that states “Run CCleaner” to continue.
   4. When asked if you want to add AVG Free Antivirus, click the “Decline” button.
   5. On the “You’re all done!” screen, click the blue “Start CCleaner” button.
   6. You will see a screen suggesting that you run a PC Health Check. Ignore that option and in the left column click on the Tools (wrench) icon.
   7. From the Tools menu, at the bottom of the options, select Drive Wiper.
3. DRIVE WIPER — Using the CCleaner Drive Wiper utility you can erase an entire drive or just the remaining unused portions of the drive. Once you’ve determined the scope of the erase process, continue to the next selection which determines the erase method.
   • ERASED UNUSED — If you performed a factory recovery of a computer, you could consider using the “Free Space Only” option. The freshly installed operating system and original programs will overwrite some of the drive’s data. The rest of the drive can be securely erased using the “Free Space Only” option. This was mentioned under the Alternative Erase Method heading at the top of this page.
   • ENTIRE DRIVE — Choose the “Entire Drive (All data will be erased)” option to securely erase an external drive. Make sure you are selecting the external drive, and be very sure not to have any other USB flash drives or other drives plugged into your computer. You may want to use your file explorer to ensure that the drive name and letter correctly correspond with the drive you want to erase.
4. ERASE METHOD — For the Security option you will select the erase method. Three passes is probably adequate for most people’s privacy concerns. Even a single pass would be enough to cause files not to show up as recoverable with typical data recovery methods. It is believed that extremely sensitive equipment can sense underlying previous magnetic states of bits and bytes on a drive.
   • 1 PASS — A simple overwrite will write data to your drive that overwrites any existing data. This would make it difficult for most standard data recovery programs to retrieve files.
   • 3 PASS — Anyone with a heightened concern about data security and privacy may want their drive to be written over three times. This would make it very unlikely that anyone could easily recover old user files.
   • 7 PASS — The more passes performed, the more secure the erase is. A 7 Pass process would be very secure.
   • 35 PASS — The DoD (Department of Defense) and various three-letter agencies may use as many as 35 passes to be absolutely certain data is overwritten securely in cases where data leaks could result in a national security concern.
5. DATA RECOVERY — For additional security, you can obtain data recovery software and scan your erased drive for any recoverable files. The software should find nothing, or perhaps only some remnants of the secure erase process.
6. REMOVE SOFTWARE — Once you’ve completed the process above, remove any software you used to keep your computer free of unneeded software.