Change the boot order in my PC — decision flow & steps

You change a PC’s boot order either for a single boot (installer, recovery USB, PXE) or to make a device the default every startup. Use the one-time boot menu for a single run and open the firmware (UEFI/BIOS) to change persistent boot priority. This guide gives prechecks, one-time and persistent steps, how to tell UEFI from legacy BIOS, what can block devices (Secure Boot, Fast Boot, RAID/Intel RST), how to verify the machine actually booted from the device, and how to undo changes safely.

Quick checklist: temporary one-time boot or permanent change?

Answer: Decide now whether you need a single boot or a lasting change. That determines the path you follow and keeps you from changing firmware when you only need a one-off boot.

• One-time boot: use this for a single recovery or installer run and avoid permanent firmware changes.
• Persistent change: use this when a device should be first every boot, for example a new OS drive, or when you manage many systems and want consistent startup behavior.

Prerequisites — what you must have before touching firmware or trying a one-time boot:

• A bootable media already created and tested where possible (USB, DVD, or accessible PXE server).
• Any firmware/supervisor password for the machine, or explicit permission from the device owner.
• Mains power for laptops during firmware changes.
• Admin access to the OS if you plan to use an OS method to enter firmware settings.

How to tell whether your PC uses UEFI or legacy BIOS:

1. From Windows: open System Information (msinfo32) and check BIOS Mode for UEFI or Legacy.

2. From Linux: check whether /sys/firmware/efi exists. If it exists, the system booted UEFI.

ls /sys/firmware/efi || echo "No EFI present"

3. Visual clues in firmware: UEFI menus show named entries such as UEFI: SanDisk and graphical menus. Legacy BIOS shows plain text lists and may say "Legacy" or "CSM".

Before proceeding, quick checks:

• Ensure the media is actually bootable. Recreate it with an appropriate tool (Windows Media Creation Tool, Rufus, dd, or your distro’s recommended writer).
• Know whether Secure Boot, Fast Boot, or RAID/Intel RST are used; these often prevent a device from appearing.
• If you lack the firmware password, contact the device owner or admin; do not attempt hardware resets without model-specific instructions and permission.

Path A — One-time boot (fast, reversible)

Answer: Use the one-time boot menu to boot a device once without changing firmware. This is the quickest, safest way to run installers or recovery tools one time.

1. Make or verify bootable media.

• Create a UEFI-capable USB for modern installers and signed recovery tools.

2. Plug the USB or insert the DVD before powering on or before rebooting.

3. Identify the one-time boot key for your machine. Common examples: Dell F12, HP Esc then F9, Lenovo Novo button or F12, ASUS F8, Acer F12. Custom desktops often show the key on the POST splash screen.

4. Reboot and press the boot-menu key repeatedly until the boot menu appears.

5. In the boot menu, select the device you prepared and press Enter. Expect either a simple physical list or named UEFI entries such as UEFI: SanDisk or Windows Boot Manager.

6. Confirm the system boots from the chosen media.

• Expected results: a Windows installer shows its installer UI; Linux live media shows a distro boot menu or desktop; PXE starts a network boot sequence.

7. If it fails to boot, power off, remove the media if needed, and boot normally. If the menu option is missing, see the troubleshooting section.

Path B — Persistent firmware change (UEFI and legacy BIOS)

Answer: Use persistent firmware changes when you need a lasting boot priority switch. This lets the machine try the chosen device first on every startup until you change it again.

1. Enter firmware settings.

• Watch the vendor splash for a key (Del, F2, F10, Esc, F1). If you miss it, use Windows: Settings → Recovery → Advanced startup → Restart now → Troubleshoot → Advanced options → UEFI Firmware Settings → Restart.

2. Confirm whether the firmware is UEFI or legacy BIOS by reading the menu text.

• UEFI uses named entries and may show GUID-style paths.
• Legacy BIOS shows simple device lists and Move Up/Move Down commands.

3. Change the boot order in UEFI.

• Find the Boot or Boot Priority page. You may see two lists: named UEFI boot entries and a physical device list.
• Use on-screen keys (often +/-, F5/F6, or drag-and-drop) to move the desired UEFI entry or device to the top.
• If you need to add an entry, use "Add Boot Option" and pick the device path.

4. Change the boot order in legacy BIOS.

• Open the Boot menu, select the device to move, then use Move Up/Move Down or Enter to reorder. Place the desired device first.

5. Save and exit the firmware. Confirm the prompt to save changes and allow the system to reboot.

• Expected result: the system tries the first device. If it fails, it proceeds down the list. If you set an internal drive first, that OS should load; if you set USB first, the system attempts the USB media.

6. If firmware is password-protected and you lack the password, contact the device administrator or vendor support; do not attempt a hardware reset unless you have explicit, model-specific instructions and permission.

Cautions and blockers: Secure Boot, Fast Boot, RAID/Intel RST, and firmware passwords

Answer: Secure Boot, Fast Boot, RAID/Intel RST, and firmware passwords commonly hide or block boot devices. Check these settings before blaming the media.

• Secure Boot: Secure Boot rejects unsigned or incorrectly signed bootloaders. An unsigned USB may not appear or will fail to boot.

Options:

• Use a signed image.
• Enroll a key.
• Enable vendor setup mode temporarily.
• Disable Secure Boot in firmware to test.

• Fast Boot (firmware) and Fast Startup (Windows): Fast Boot can skip device initialization and hide USB devices in the boot menu.

Actions:

• Disable Fast Boot in firmware.
• Turn off Windows Fast Startup: Control Panel → Power Options → Choose what the power buttons do → uncheck Turn on fast startup.
• Fully power-cycle the machine.

• RAID / Intel RST: When a storage controller runs in RAID/Intel RST mode, firmware may present a single logical device and hide member drives.

• Firmware (supervisor) passwords: These block changing boot priorities. If you don’t have the password, contact the administrator or vendor; avoid CMOS clearing or hardware removal unless you have model-specific guidance and authorization.

• Vendor quirks: Some systems list USB keys under names like USB HDD or by brand; check submenus if you don’t immediately see your device.

Completion: verify the change worked and quick recovery if it didn’t

Answer: Verify the machine booted from the device you intended, then follow quick recovery steps if it didn’t. Use OS tools or firmware cues to confirm and restore previous settings if needed.

Verify in Windows:

1. Check System Information for BIOS Mode and confirm the boot device using Disk Management or bcdedit.

bcdedit /enum

Verify in Linux:

1. Check what mounted as root and recent boot messages.

lsblk -f
journalctl -b | head -n 50

Verify from firmware cues: many UEFI menus show the last selected or current boot entry. If firmware showed UEFI: <device> and the OS started, that confirms the boot device.

Quick recovery steps if it didn’t boot:

• No boot device: remove external media and try a normal boot.

• If an internal OS fails after you changed controller modes, revert the controller setting (for example, AHCI ↔ RAID) and reboot.

• USB not listed: try a different USB port (prefer rear ports on desktops), recreate the media with a UEFI-capable method, disable Fast Boot, temporarily disable Secure Boot to test, or try the USB on another machine.

• OS load errors after ordering change: boot recovery media using the one-time menu and repair the OS (Windows Recovery tools or grub repair for Linux). You can also restore firmware defaults in the firmware menu: choose "Restore Defaults" or "Load Optimized Defaults", save and exit.

Revert persistent changes:

1. Re-enter firmware, move the previous device back to the top, or select "Restore Defaults", then save and exit.

Expected final state after success: the machine boots from the device you intended. Installers or live environments appear for USB/DVD, or the expected OS starts on an internal drive. If you used a one-time boot, firmware settings remain unchanged and the next startup follows the original persistent order.

Conclusion

Follow the path you planned: use the one-time boot menu for a single run and change firmware only when you need a lasting result. Check blockers—Secure Boot, Fast Boot, RAID/Intel RST, and firmware passwords—before troubleshooting a missing device. Verify the boot with OS tools and restore firmware defaults if you need to undo changes.