How can I set bootable USB or CD/DVD in BIOS or UEFI?

To boot from a USB, CD, or DVD device, make sure that device has boot priority over the internal hard drive or SSD. The exact steps depend on whether your system uses modern UEFI firmware or legacy BIOS — most computers manufactured since around 2012 use UEFI, though many still include a "Legacy" or "CSM" (Compatibility Support Module) mode for backward compatibility.

A typical method to access the boot/firmware settings screen is to press Esc, F1, F2, F8, F10, F11, or F12 during the boot sequence (the exact key depends on the motherboard or laptop manufacturer). On newer Windows 10/11 systems with UEFI and Fast Startup enabled, the boot screen can flash by too quickly to catch the key press; in that case, it's more reliable to open Settings > Recovery > Advanced startup, click Restart now, and then choose Use a device or enter UEFI firmware settings directly from that menu.

While in the setup utility, you typically cannot use a mouse — use the keyboard arrow keys to navigate.

UEFI

On UEFI systems, boot priority is configured similarly, but with a few important differences to check:

  1. Boot mode (UEFI vs. Legacy/CSM): Most bootable KillDisk media created for modern systems supports UEFI natively. If the boot USB isn't detected, check whether the firmware is set to "UEFI only," "Legacy only," or "Both" — and match this to how your boot media was created.
  2. Secure Boot: Many UEFI systems ship with Secure Boot enabled, which only allows digitally signed bootloaders to run. If your USB or CD doesn't boot, or the system silently falls back to the hard drive, try temporarily disabling Secure Boot in the firmware settings.
  3. Fast Boot / Fast Startup: This feature speeds up startup by skipping some hardware initialization and can prevent USB devices from being recognized in time. Disable it in the firmware if the boot device isn't detected.
  4. One-time boot menu: Instead of permanently changing boot order, most UEFI systems offer a one-time boot device selection menu — commonly accessed with F12, F11, or Esc right after powering on. This is often the fastest way to boot from a USB or CD without altering saved firmware settings.

Legacy BIOS

Boot priority is configured under a Boot tab, where system devices are listed in order of priority. The first device in the list has first boot priority — for example, to boot from a USB drive instead of the hard drive, move the USB device to the top of the list. Before setting boot priority for a USB device, plug it into a USB port so it's detected as an available option.

General tips

  1. Always plug in the USB device before entering firmware setup so it's visible in the device list.
  2. Save changes and exit — the system will restart with the new settings applied.
  3. If the device still isn't detected, verify the boot media was created in the correct format (UEFI vs. Legacy/MBR) for your target system, since a mismatch is one of the most common causes of a "boot device not found" error on modern hardware.
CAUTION:

Using an incorrect BIOS/UEFI setting can cause a system malfunction. Please follow the firmware guide provided by your computer or motherboard manufacturer. If you're unsure how to change a setting, it's safer to leave it at its default value, or use the one-time boot menu instead of permanently modifying boot order.