Introduction
A Bootable USB is used to install or recover an operating system. This article explains how to prepare installation media and the relevant UEFI, Legacy BIOS, GPT, and MBR considerations for Windows and Linux.
Data on the USB drive will be erased
Creating bootable media formats or rewrites the selected USB drive. Back up every file you need from the USB drive before you continue and verify that you selected the correct device.
01 — Prerequisites
- A USB drive with sufficient capacity for the selected operating-system image.
- A valid ISO file downloaded from the official operating-system vendor or distribution.
- A backup of all existing data on the USB drive.
- Knowledge of the target system firmware type: UEFI or Legacy BIOS.
02 — Create a USB Drive with Rufus
Open Rufus and select the intended USB drive in Device. Under Boot selection, choose the downloaded ISO. Review the Partition scheme and Target system values before starting the write process.
GPT and UEFI
Use GPT with UEFI for most modern systems.
MBR and BIOS/UEFI-CSM
Use MBR with Legacy BIOS or UEFI-CSM when the target computer requires the older compatibility mode.
03 — Create Windows Installation Media
For Windows, use the official Microsoft Media Creation Tool when it is available for the Windows release you need. The tool guides you through selecting the Windows version and creating installation media on a USB drive.
04 — Create a Linux USB Drive
Download the ISO from the official website of the Linux distribution. Write the image with Rufus or balenaEtcher according to the distribution documentation, then safely eject the USB drive after the process finishes.
05 — Boot from USB
Insert the prepared USB drive into the target computer, restart it, and open the Boot Menu or BIOS/UEFI setup. Select the USB device as the temporary boot option or adjust the boot order as required by the system.
06 — Check Secure Boot
Disabling Secure Boot is not always necessary. Keep it enabled whenever the operating-system image and boot media support it. Change the setting only when you have identified a compatibility issue and understand the security impact for the target device.
07 — Common Errors
USB not detected
Try another USB port, confirm that the drive appears in the firmware boot menu, and recreate the media if necessary.
The ISO is corrupted or untrusted
Download the ISO again from the official source and verify the published checksum when the distribution provides one.
Incorrect GPT or MBR selection
Match the partition scheme and target system to the firmware mode of the target device.
Boot failure or UEFI issue
Review the selected boot entry, UEFI/Legacy mode, Secure Boot compatibility, and the media-creation settings.
Best Practices
- Back up the USB drive before writing an image because its content will be erased.
- Download Windows and Linux images only from official vendor or distribution sources.
- Verify the ISO checksum when a publisher provides one.
- Label the USB drive with its operating system and version after creating it.
- Test the media on an authorized non-production device before relying on it for a critical deployment.
Troubleshooting
If the system does not boot from the USB drive, check that the ISO is valid, the correct USB device was selected, the firmware mode matches the media, and the target computer is configured to boot from USB. Recreate the USB drive from a freshly downloaded official ISO if the problem continues.
Frequently Asked Questions
Will creating a Bootable USB erase the flash drive?
Yes. Creating the installation media overwrites or formats the selected USB drive, so back up its contents first.
Should I always disable Secure Boot?
No. Keep it enabled unless a confirmed compatibility issue requires a change.
Which partition scheme should I select?
For most modern UEFI systems use GPT. Use MBR only when the target system requires Legacy BIOS or UEFI-CSM compatibility.
Conclusion
Create bootable media from a valid official ISO, select the USB drive carefully, match GPT or MBR to the target firmware, and test the boot process. Protect the USB data first because the creation process deletes existing files on the drive.
