Windows 10, how to format and erase data safely

When we have to sell or give away our PC it is important to erase all traces of our documents and programs, here's how to do it in a few clicks

When we are about to give away or sell a computer one of the many steps to take is to format the hard drive. The reason why is not at all difficult to explain: in the hard disk of the computer you can find everything, from vacation photos to work documents, passing through e-mail and home banking access data.

To prevent the person who will use our old PC from recovering files, it is necessary to perform a thorough formatting. Quick formatting, in fact, deletes only the partition table, while the files will remain in their "place" until they are overwritten by new information, making it possible to restore them. A shrewd user, therefore, will have to spend some of his time to prevent his friend (or, even worse, a stranger) from being able to get hold of his photos or other personal information.

How to securely format your hard drive with Windows 10

To perform a secure format on your computer you have to rely on the Command Prompt and use some old instructions that date back even to MS-DOS. Nothing too complex, let's be clear, but it should be noted that you won't be able to use any wizard or graphical interface: you'll have to "work" with the keyboard and be very careful with the commands you type.

First of all, you need to find the letter that identifies the hard drive or partition to be formatted. Open File Explorer and, in the left column, click on the entry This PC. On the screen that appears, look for the Devices and Drives section: here you will find listed all hard disks inside the computer and all partitions created by the user. The letter that identifies the drive is at the end of the name, enclosed in round brackets (usually C:, but it could also be D:, E: or F: if you have two or more partitions or hard drives).

A questo punto si deve aprire il Prompt dei comandi come amministratore (dalla barra del menu Start digitare la stringa “cmd" nel campo di ricerca, cliccare con il tasto destro del mouse sulla voce Prompt dei comandi e scegliere Esegui come amministratore) e, nella finestra con sfondo nero, digitare il comando “format nome_volume /P:passaggi“, dove

  • format è il comando per la formattazione
  • nome_volume è la lettera che identifica il disco (C, ad esempio)
  • /P passaggi è il numero di volte che si vorrà sovrascrivere i dati del disco con informazioni casuali.

Se, ad esempio, si volesse cancellare in modo sicuro la partizione D con 5 passaggi, nella finestra del Prompt dei comandi si dovrebbe scrivere “format D /P:5". In questo modo Windows 10 cancellerà il contenuto del disco sovrascrivendo i dati per cinque volte. Va da sé che al crescere del numero dei passaggi aumenterà anche il tempo necessario per completare la procedura.