What Happens if I Erase My Hard Drive?

By William Jensen

Deleting a file may not permanently erase it.
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When you erase your computer's hard drive, many different consequences ensue. Data, software, settings and the entire operating system all disappear. At the same time, some of this material may still linger on the hard drive, even as it appears to have vanished. Fully clearing the drive often proves time-consuming, but it can solve many technical problems and improve privacy.


Documents, images, spreadsheets and all sorts of other files disappear when you erase your hard drive. Some additional examples include Web browser history records, high score lists for computer games and logs created by antivirus software. However, some data may remain hidden on the hard drive. Deleting or reformatting isn't very effective for permanently removing files, according to the U.S. Department of Homeland Security. Computer users must erase data then overwrite it with new material to remove it more certainly; doing this several times proves most effective. Some computer programs perform this task automatically.


Erasing your hard drive also removes all computer software installed on it, including things like word processors, Web browsers, games and email applications. To use such programs in the future, you will have to reinstall them from discs or download them from the Internet again. In the process of clearing the hard drive, you will also erase any program updates or extra drivers downloaded from the Internet. A positive aspect of fully removing all software is that you erase any viruses on the hard drive as well.


Many software and operating system settings become lost when you erase the hard drive. These include "Preferences" and "Properties" of Web browsers, printers, mice, keyboards, word processors, fonts and desktop styles. Saved usernames and passwords will also disappear. However, the computer's main BIOS (Basic Input Output System) settings should remain in place, along with any manual hardware settings activated using DIP switches or jumpers. Consider making a note of some important settings before you erase the hard drive.

Operating System

The operating system will also vanish when you erase your computer's hard drive; the computer will not fully boot up until you install a new operating system or insert a bootable disc. As with software programs, any additional operating system updates installed from discs or Internet downloads will be lost as well. Some computers have secondary hard drives used only for programs and data; erasing this type of drive will not result in the loss of the operating system or most settings.