How do I permanently Delete files from my hard drive?

by
How do I permanently Delete files from my hard drive

Deleting files you no longer need can free up valuable storage space on your hard drive. When you delete a file in Windows, it may seem like the file is gone for good, but that is often not the case. Deleted files can remain on your hard drive taking up space until they are overwritten with new data. If you want to make sure a file is permanently deleted and unable to be recovered, you need to take additional steps beyond just deleting it.

Why Deleted Files Can Be Recovered

When you delete a file in Windows, either by hitting delete, dragging the file to the recycle bin, or using the SHIFT + DELETE keyboard shortcut, Windows simply marks the space occupied by that file as available. The contents of the file remain on the hard drive until that section is overwritten by new data. This makes it possible for data recovery software to scan the hard drive and rebuild files that have been deleted.

Some reasons you may want to ensure a file is permanently deleted and unable to be recovered include:

  • The file contains sensitive personal or financial data
  • The file contains confidential business data
  • The file contains intellectual property you want to protect
  • You are donating, selling or recycling your computer and want your data gone for good

Simply deleting sensitive files may seem sufficient, but data recovery software makes it possible for deleted files to be restored. To prevent that, take steps to permanently scrub deleted files from your hard drive.

Permanently Deleting Files Using Window’s Built-In Tools

Windows provides a couple different built-in options for permanently deleting files.

Using SDelete

SDelete is a command line tool that comes as part of the Windows Server Resource Kit Tools. To use it:

  1. Download the Windows Server Resource Kit Tools installer here: https://www.microsoft.com/en-us/download/details.aspx?id=17657
  2. Run the installer and select to install SDelete
  3. Open the Command Prompt as an administrator
  4. Navigate to the folder containing the file(s) you want to permanently delete. For example, to delete a file named secret.txt on your desktop:
    cd C:\Users\YourUserName\Desktop
  5. Run the SDelete command. To permanently delete secret.txt:
    sdelete secret.txt

SDelete overwrites the space used by the deleted file making recovery impossible. Keep in mind SDelete is a command line tool, so it’s not as user friendly as some other options covered later.

Using Cipher

Cipher is another command line tool built into Windows that can be used to permanently delete files. To use it:

  1. Open the Command Prompt as an administrator
  2. Navigate to the folder containing the file(s) you want to permanently delete. For example, to delete a file named secret.txt on your desktop:
    cd C:\Users\YourUserName\Desktop
  3. Run the Cipher command with the /w switch to overwrite free space on drive. For example:
    cipher /w:C

This will overwrite any deleted data on your C: drive making it unrecoverable. One downside to this method is that it overwrites all free space, not just the space used by the file you want permanently deleted.

Using Third-Party Tools to Permanently Delete Files

If you want a more user-friendly tool for permanently deleting files, several third-party utilities are available. Here are some of the best options:

Eraser

Eraser (https://eraser.heidi.ie) is a free open source tool for completely removing sensitive data from your hard drive. To use it:

  1. Download and install Eraser
  2. Run Eraser and add files or folders you want to permanently delete
  3. Select a deletion method – the default one pass overwrite is sufficient for most uses
  4. Click Erase to permanently scrub the files from your hard drive

Eraser gives you configurable options for how files are overwritten, letting you balance deletion speed with security.

Softonic Disk Wipe

Softonic Disk Wipe (https://disk-wipe.en.softonic.com) is another free tool for permanently deleting files. To use it:

  1. Download and install Softonic Disk Wipe
  2. Select a disk to wipe – this will permanently delete all files on that disk so be cautious
  3. Select a wiping method – Multipass is ideal for permanantly deleting all traces of your data
  4. Click Start Wipe to begin permanently deleting all files on the disk

Disk Wipe is very simple to use but take caution as it can erase entire drives.

Active@ KillDisk

Active@ KillDisk (https://www.killdisk.com) is a more advanced paid tool for permanent file deletion. Key features include:

  • Permanently deletes individual files or entire drives
  • Supports a variety of advanced deletion methods like DoD 5220.22-M or Gutmann wiping patterns
  • Schedule deletion jobs to run at a specific data and time
  • Wipe unused disk space to scrub deleted files
  • Securely wipe SSD drives

KillDisk provides everything you need to thoroughly wipe sensitive data from your hard drive.

Permanently Deleting Files on Solid State Drives

Permanently deleting data on traditional hard disk drives involves overwriting the data. Solid state drives (SSDs) store data differently than traditional hard drives, so this method won’t work as effectively.

Wiping utilities utilize two methods for securely deleting SSD drives:

ATA Secure Erase

ATA Secure Erase sends a special command to the SSD that securely erases all data on the drive. It has the benefit of being very fast. However, not all drives support this command.

Overwriting Cells

If the SSD drive does not support ATA Secure Erase, the wiping utility will overwrite all SSD cells to delete the data. This takes much longer but works on any SSD.

Quality SSD wiping tools like Active@ KillDisk will first attempt an ATA Secure Erase and fall back to overwriting cells if the drive does not support it.

Permanently Deleting Individual Files vs Full Drive Wipes

Some data wiping tools like SDelete and Eraser let you target individual files to permanently delete. Other tools like Active@ KillDisk and Disk Wipe wipe entire partitions or drives.

Permanently deleting individual files has the lowest risk of accidentally deleting data you didn’t intend to remove. But if your goal is to scrub all deleted files from a drive before selling or disposing of it, a full drive wiping utility is the easiest approach.

In summary:

  • Use individual file shredding when you just want to permanently erase a few sensitive files
  • Use a full drive wipe when selling, donating or recycling a drive to erase all deleted files

Should You Physically Destroy Drives

Some organizations mandate physically destroying old drives before disposal to prevent data leaks. While physical destruction provides an extra layer of safety, a multipass software wipe is generally sufficient for most uses. Exceptions include:

  • Drives containing highly classified data
  • Drives used to store especially sensitive data like medical records, trade secrets, or proprietary algorithms.

For most home and business uses, software wiping provides adequate safety at a much lower cost than destruction. But for truly sensitive data, physical destruction adds extra peace of mind.

Securing Deleting Files When Donating or Selling Computers

When preparing to sell or donate your computer, you want to make absolutely sure all personal and sensitive files are wiped from the hard drive. Here are some best practices to follow:

  • Back up any files you want to keep onto an external drive or cloud storage. Once you wipe the drive, all data will be permanently gone.
  • Use a data wiping utility like Active@ KillDisk to perform a full drive wipe. This will scrub all deleted files.
  • For an SSD drive, make sure to use a wipe utility that utilizes ATA Secure Erase like KillDisk.
  • Remove any internal hard drives that you are keeping so they are not wiped accidentally.
  • Fully wipe USB flash drives and external hard drives as well if they are being sold or donated.

Following this process will make sure sensitive files cannot be recovered from any storage devices before they leave your possession.

Conclusion

While simply deleting files may seem sufficient, it’s possible for deleted data to be recovered using forensics tools. To make sure your deleted files are permanently scrubbed from a hard drive, use a secure deletion tool like SDelete, Cipher, Eraser, or Active@ KillDisk. For maximum safety when disposing of a drive, perform a full drive wipe to scrub all deleted files before sale or donation. With the prevalence of data leaks and identity theft, taking proper measures to permanently destroy sensitive information is critical when recycling or selling computers and drives.