How to Erase Computer Hard Drives

By Jason Gordon

The hard drive, the storage heart of any modern computer, contains all the files, folders, and programs, including the operating system, that makes your computer run. For a number of reasons, it sometimes becomes necessary to erase your hard disk. One reason to erase your hard drive is when files have become corrupted or you have a virus or other malware that is difficult to remove. Another reason to erase your hard drive is if you are selling or donating your computer and are worried about your personal data being found and used.

Step 1

Back-up any important data on other media, such as CD or DVD-ROMs, before attempting to erase your hard drive. After erasing your hard disk, it will be very difficult, if not impossible, to recover your data.

Step 2

Do is a disk format if you are trying to erase a hard drive only to reinstall your operating system and start with a blank slate. If you purchased your computer from a vendor such as Dell, HP or Compaq, you should have received a "system recovery" disk that will allow you to format the drive and reinstall Windows. Simply place the disk in the drive and follow the on-screen instructions for formatting your drive.

Step 3

Use a DOS command, another way to format. To do this, open a command link prompt. Click on Start and type in "cmd." A Command Line window will open. Type in "format c: /u" This is called an unconditional format and is more secure than a quick format which can be done by typing "format c: /q" where "c" is the drive letter of the hard drive you want to erase. After formatting the drive, you will have to use your operating system CD to reinstall Windows.

Step 4

Keep in mind that if you are donating or selling your computer and are worried about your personal data being taken, a format may not be enough. It is possible to recover the data on a formatted disk with specialized methods or software. A more secure way to erase your disk if you are concerned about your personal data being used is called a disk wipe. Disk wipes can be performed using both free and commercial software found on the web (see Resources below).

Tips & Warnings

  • Even after using a disk wipe program, a professional with unlimited time and money could still possibly obtain some of the erased data. The only way to be completely sure that your hard drive's data is inaccessible is to physically destroy the drive.