How to boot the system from bootable USB flash drive/CD-ROM?

MyRecover Post By MyRecover Updated December 6, 2023

What is bootable media?

Bootable media refers to any storage medium, such as a CD, DVD, USB flash drive, external hard drive, or other removable media, that is configured in a way that allows a computer to start or "boot" from it, even in the absence of an active operating system on the computer's internal storage. This bootable media typically contains the necessary system files and an operating system to initiate and run the computer.

Here are the various uses and advantages of bootable media:

Operating System Installation: USB boot allows you to install a new operating system, such as Windows, Linux, or macOS, without relying on a CD or DVD. This is particularly useful on modern computers that lack optical drives.

System Maintenance and Troubleshooting: With USB boot, you can access system maintenance and troubleshooting tools to fix operating system issues or detect hardware failures. This includes using boot repair tools, recovery consoles, or other system maintenance utilities.

Portable Operating System (Windows To Go): You can create a portable operating system environment that enables you to use the same OS and applications on different computers without the need to install them on each machine. This is useful for mobile work or secure computing on public computers.

Data Recovery: In case your computer fails to boot, USB boot tools allow you to access data on the hard drive for backup or restoration of important files.

Security and Privacy: Some security-focused operating systems and tools can boot from a USB drive to ensure that no traces are left behind after each use. This is useful for privacy protection and security audits.

Creating Bootable Portable Applications: Many portable applications can be packaged onto a USB boot drive, allowing you to carry them with you without needing to install them on each computer.

How to Boot from USB on Windows?

Generally, BIOS (Basic Input Output System) boot sequence dictates the order in which devices are searched for the necessary software to start the computer. By default, most computers are set to boot from the hard drive, but when using a USB or CD/DVD for booting, it's necessary to adjust this sequence. Setting the USB device or CD/DVD drive as the primary boot option ensures the computer looks for the required software in these external media sources first before resorting to the internal hard drive. This adjustment allows you to initiate the computer using an operating system or software stored on the USB or optical disc, granting flexibility and the ability to troubleshoot or install new systems when needed.

Here we take the ASUS motherboard as an example to introduce how to boot from USB.

Enter boot menu by using hotkey

You can press the hotkey to enter the Boot Menu when booting, which allows you to quickly select the boot device without entering the BIOS to set the first boot device.

1. Press F8 on the initial startup screen to enter the Boot Menu.

2. Use the arrow keys on your keyboard, select the USB drive and press Enter. The computer will immediately restart and boot from the USB drive.

Boot Menu

Tips: This method does not enter the BIOS to modify the boot sequence, so it will still boot from the previously set device (usually the hard disk) when the computer boots next time.

Enter into BIOS to change boot sequence

You can boot the computer into BIOS configuration to set the boot sequence and USB as the priority boot option.

1. Start by plugging the thumb drive into a USB port. Then to change the BIOS boot sequence.

2. Press the Power button on your computer.

3. During the initial startup screen, press ESC, F1, F2, F8, or F10 (depending on the company that created your version of BIOS, a menu may appear). Here we take ASUS motherboard as an example, press DEL to enter BIOS Setup, the setup utility page will appear.

Note: If you don't know which shortcut key to press to enter the BIOS, you can Google your motherboard brand and version to find out what the shortcut key is, or contact the computer manufacturer directly.

4. After entering the BIOS configuration, use the cursor to click [Advanced Mode] that the screen displayed.

Advanced Mode

5. Using the arrow keys on your keyboard, select the [Boot] tab. All available system devices will be displayed in order of their boot priority, you can reorder the devices here. Move USB to be first in the boot sequence.

Boot Sequence

Note: If you cannot find USB or Removable Devices among the device options, your BIOS may list it under Hard Drive Devices. In that case, you'll need to: Move Hard Drive Devices to the top; Expand to show all hard drive device options; and Move the USB device to the top of that hard drive list.

6. Save the changes and then exit the BIOS Setup. The computer will reboot using the new settings, booting from your USB drive.

Stay alert! Depending on your BIOS, you may be prompted with a message to "Press any key to boot from an external device", and you will only have a few seconds to respond. If you do nothing, your computer will go to the next device in the boot sequence list, which will likely be your hard drive.

In the future, your computer will first check the USB port for boot media when starting up. That won't be a problem since the BIOS will move to the next device in the boot sequence unless you keep the boot media in the USB port. Then the system will launch from that device every time.

Disable Secure Boot

In some cases, Secure Boot needs to be turned off to be able to boot the computer from USB.

To disable Secure Boot, go to [Security] screen, then select [Secure Boot].

Secure Boot

After entering the [Secure Boot] screen, select [Secure Boot Control] and then select [Disabled].

Disable Secure Boot

Set USB boot with AOMEI Partition Assistant

If you can boot into Windows of the computer, with UEFI BIOS Boot Options Manager in AOMEI Partition Assistant, you can easily and quickly change EFI/UEFI BIOS Boot Options without manual entry into BIOS and complicated modification of startup entries.

UEFI BIOS Boot Option

Remember, BIOS settings can be sensitive, so be cautious while making changes. If unsure, refer to your computer's manual or the manufacturer's website for specific instructions related to your BIOS version.