No bootable device found. Boot device not found. No boot device available. Different manufacturers, one meaning: the machine woke up, went looking for something to start from, and found nothing it could use. What you do in the next ten minutes decides whether this is a two-minute settings fix or a recovery job.
The single most useful fact about this error is who is saying it. It isn’t Windows, macOS or Linux — none of them have started. It is the firmware, the BIOS or UEFI, speaking before any operating system exists. It finished its self-test, went down its list of boot devices looking for something with a bootloader on it, reached the end of the list, and gave up.
That timing tells you where the fault lives: somewhere between the firmware and the drive. Either the drive is present but the firmware can’t make sense of it, or the drive isn’t answering at all. Those two branches lead to completely different places — one ends in a menu, the other in a recovery quote — and the message itself refuses to tell you which. Fortunately, one minute in the BIOS will.
Restart and hold the setup key as it powers on — usually F2, Del, F10 or Esc, depending on the maker. Find the page that lists storage devices (often Boot, Storage, or the main information screen). Then answer one question: is your drive listed there at all?
If the drive is listed: the hardware is answering, and you are probably on the benign branch. Common culprits are a boot order that got reshuffled by a USB stick left in a port, a firmware update that flipped UEFI/Legacy or Secure Boot, or a damaged boot record after a bad shutdown. Set the correct drive first in the boot order and try again before assuming the worst.
If the drive is not listed: stop. That is the firmware telling you the disk is not responding on its own connection — a failing or failed drive, a dead controller board, a disconnected cable inside a knocked laptop, or the sudden-death pattern that SSDs are notorious for. No amount of Windows repair can fix a drive the machine cannot even see, and every further boot attempt is another spin-up on a disk that may not have many left in it.
The internet’s advice for this error is a list of writes to a drive that may be dying. Automatic Repair loops, bootrec /fixmbr, /fixboot and /rebuildbcd all rewrite boot structures — harmless on a healthy disk with a scrambled boot record, actively destructive on a disk with failing sectors, where every forced write is a chance to overwrite something you needed and to push weak areas past the point of reading at all.
The truly expensive one is the reinstall. “Just reinstall Windows and see” ends with a fresh, empty file system laid on top of your photographs. And running chkdsk on a failing drive — the other standard suggestion — puts hours of intensive reading and writing across the exact areas that are already struggling. If the drive is invisible to the BIOS, or if it clicks, buzzes, spins up and stops, or gets hot doing nothing, then the honest advice is short: power it off and leave it off.
On the invisible-drive branch the work is straightforward and it happens at hardware level, not in the operating system: the drive is imaged sector by sector on equipment that never writes back to it, the file system is rebuilt from that image, and your files come out of the copy. An SSD that vanished from the BIOS overnight usually has a controller or firmware fault behind it; a hard drive that stopped being seen after a knock or a click has a mechanical one. Both are routine — neither is fixable by booting it again and hoping.
One practical note before anything travels: the drive is what we need, not the computer. Take it out of the laptop or tower — any local computer shop will do it in minutes if you’d rather not — and send the drive itself. The diagnostic is free, single drives are a fixed £300 + VAT in the standard band, and on most jobs nothing is owed unless your data comes back. If the BIOS can see the disk, you probably need a boot-order tweak and a coffee — and we will happily say so for nothing.
Every restart is another spin-up on a disk that may be running out of them, and every “repair” writes to the one copy of your data that exists. Power it down, take the drive out, and let the free diagnostic tell you what’s actually wrong — £300 + VAT fixed in writing if recovery is needed.