To uninstall Tails from a USB stick or SD card, and use it for something else, you have to reset it.

The content of the device will be lost in the operation, but an attacker might still be able to tell that Tails was installed on that device using data recovery techniques unless you securely clean all the available disk space afterwards.

Using GNOME Disks

You might overwrite any hard disk on the computer. If at some point you are not sure about which device to choose, stop proceeding.
  1. Make sure that the USB stick or SD card that you want to reset is unplugged.

  2. Choose Applications ▸ Utilities ▸ Disks to start GNOME Disks.

    A list of all the storage devices on the computer appears in the left pane of the window.

  3. Plug the USB stick or SD card that you want to reset.

    A new device appears in the list of storage devices. This new device corresponds to the USB stick or SD card that you plugged in. Click on it.

  4. In the right pane of the window, verify that the device corresponds to the device that you want to reset, its brand, its size, etc.

  5. To reset the device, click on the Menu button in the titlebar and choose Format Disk….

  6. In the Format Disk dialog:

    1. If you want to erase all data securely, choose to Overwrite existing data with zeroes in the Erase drop-down list.

    2. Choose Compatible with all systems and devices (MBR/DOS) in the Partitioning drop-down list.

    Then click on the Format… button.

  7. In the confirmation dialog, click on the Format button to confirm.

  8. To make sure that all the changes are written to the device, click on the Eject button in the titlebar.

Resetting a Tails device from itself

If Tails is your only Linux system, you can generally reset a Tails USB stick or SD card directly from that device while running Tails.

  1. When starting Tails, add the toram boot option in the Boot Loader Menu. For detailed instructions, see the documentation on using the Boot Loader Menu.

  2. If Tails starts as usual, follow the instructions for resetting a USB stick or SD card using GNOME Disks.

    If the system fails to start, that means that the computer does not have enough memory for this operation mode. Try with another computer, or find another Linux system, such as another Tails device, to do the reset from.