This is the only way to completely delete photos and files from memory cards and flash drives, and no one will be able to recover them.
If you insecurely format a hard drive or USB device and leave it with someone, the content you have saved on it may pose a minor privacy risk. If you don't intend to reuse the hard drives or USB drives you want to format, the best way to protect your data is to destroy them using specific methods. However, if you want to reuse them, we'll show you how to securely erase the contents of your hard drives and USB drives using one of the available tools.
We chose Disk Wipe because it is a very user-friendly tool for Windows. The first thing you need to do is go to the Disk Wipe download page. Once there, click the link that appears in red with the text "Click here to download Disk Wipe," and the program will begin downloading automatically.
You won't need to install anything; simply run the downloaded DiskWipe.exe file. You'll see that its icon resembles a shield, which means that double-clicking the program will prompt you for administrator permissions. Don't be intimidated by the large window; simply click "yes" to grant it permission.
Once you open the application, in the left-hand column, select the storage device you want to delete that is linked to your computer. When you select one, its information will appear in the center section to confirm that it is the one you want. When you are sure you have selected the correct option, click Wipe Disk in the upper left corner to initiate the wiping process.
Setting up the scan process consists of three parts or options. First, you'll need to choose the file system you want to format the drive with. You can choose between NTFS, FAT, and FAT32. Select the option you want to use and click the Next button to continue.
Now comes the most important part of the process: choosing the scan mode. You can choose between a single, simple scan or a 35-scan scan. The higher the number, the more certain you are that all the data will be scanned, although the process will take longer.
However, since what you want here is to permanently delete your data, choose the last option, Peter Gutman's 35 passes, and then click "Next" to continue. Of course, make sure you do this when you can leave your computer alone, because depending on the size of your USB, SD, or external hard drive, the process could take a few hours.
That's it; the process has started, and the progress will be displayed in the application window. Be patient and wait until it's completely finished if you don't want to damage your storage drive.
Link: Disk Wipe