How to Erase a Hard Drive Completely

By Josienita Borlongan

Selling or donating your old computer means you need to erase your hard drive completely. And "completely" is key. Without properly removing your files, you risk security issues with your data. Deleting files and formatting hard drives are not permanent, as software programs can recover deleted files. Choose the level of permanence you'd like to ensure you can get rid of an old computer drive without risking your data security.

Things You'll Need

  • Windows installation disk

Step 1

Back up your data. When you erase your hard drive completely you can't recover your files. Backing up ensures that your data is still available, should you realize you're missing a critical file or folder.

Step 2

Reformat the drive if you're simply passing it on to a trusted family member, such as a child who needs a computer for school work. Reformatting deletes the files and applications on the disk, making it ready to receive new data. Insert the Windows installation disk and start up your computer. Follow the on-screen instructions to reformat your hard drive, including repartitioning and installing Windows.

Step 3

Use a commercial utility software to provide greater security. These software programs write random numbers and symbols onto your drive, making the old data indecipherable. They're best used if you're donating an old computer. Darik's Boot and Nuke as well as Eraser are free to download and use (full link in Resources). Acronis is a low-cost alternative (full link in Resources).

Step 4

Run the selected program multiple times if you need. While a single process, which can take several hours, is typically sufficient, multiple passes further wipe out the data, minimizing the potential to retrieve anything from the hard disk.

Tips & Warnings

  • There are other ways that you can use DBAN to delete your hard drive and you can find out more information by reading important information online (see Resources) find out more.
  • There are other methods available for download for free or for a fee. Researching and comparing these methods will ensure that you will be able to complete this task successfully.
  • Once you have wiped out your hard drive, you cannot recover the wiped data.