A special parameter in the Windows 11 Format command will overwrite all data on a hard drive with random numbers, eliminating access to sensitive information.

Whether it is used in a business setting or as a personal device, your computer is likely to have sensitive, private data stored on its hard drive. When the useful life of your Windows 11 computer is over and you are ready to recycle or perhaps give it away, it’s important to make sure all sensitive data is removed completely. Windows 11 has a tool that can do this, but like so many of Microsoft’s features, it is hidden someplace where you would not think to look.

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With the release of Windows Vista, Microsoft introduced new features for the old DOS holdover known as the Format command. One of these parameters (/P) will not only format a hard drive for Windows operating system use, but it will also overwrite all data already on the drive with random numbers. This process effectively erases and replaces all existing data with meaningless random data.

Remove and overwrite all data on a hard drive for free

Before we can use the format command in this manner, we first must boot our device with a Windows 11 Recovery Drive. To create a recovery USB drive, if you do not have one already, type “create a recovery drive” into the desktop search tool and click the appropriate search result.

For this purpose, you don’t need to include system files but having a complete recovery drive for Windows 11 on hand is always recommended. You will need at least 32GB of storage to include all the system files. If you opt to leave out system files, all you need is 1GB. Make your selection (Figure A), and then press the Next button.

Figure A

In Windows 11, overwriting the data format.

Choose the appropriate USB drive (Figure B), and then click the Next button. It will take a few minutes to create the recovery drive. Click Finish when it has completed the process.

Figure B

In Windows 11, another view of overwriting the data format.

Now, insert your Windows 11 Recovery Drive into the PC you wish to wipe with the format command and boot it using the USB drive rather than the installed operating system. The most efficient way to accomplish this is to press and hold down the Shift key while you select Restart from the shutdown menu of the Start Button (Figure C).

Figure C

In Windows 11, overwriting the data format.

When you reach the troubleshooting startup mode, select the Troubleshoot | Advanced Options | Command prompt from the menu. In the Command prompt screen (Figure D), type this command:

Format C: /P:4

Figure D

Windows 11 tutorial about how to overwrite a data format.

This command will format the C drive and overwrite the data with random numbers four times. You can change the drive specification and the number of passes to suit your particular preferences. In this example, no operating system files will be installed.

Note: This procedure does not meet the strictest standards for overwriting sensitive data on a hard drive, but it works well under most conditions. It is highly unlikely that whatever data once existed on your PC will ever be retrieved. Regardless, this command should be used with caution.