Behind this error sits a single question with two very different answers: can the computer still see the drive it’s supposed to start from? Sixty seconds in the BIOS answers it — and everything about your next move, your risk, and your files hangs on which branch you land in.
Open the BIOS and look for the drive. Listed there but not booting → a software-layer fault, usually very recoverable. Missing from the list → the drive or its connection has failed, and it’s a hardware job.
When you press power, the machine’s firmware wakes, counts its hardware, and walks down its boot list looking for a device carrying a startable operating system — checking each candidate for the signature and boot files that say ‘start here’. The error on your screen is the firmware reporting that the walk ended empty-handed. Notice what it did not say: nothing about your documents, your photos, or the drive’s contents generally. The search for a working ignition failed; the rest of the car hasn’t been inspected at all.
Before the BIOS fork, clear the two trivial impostors: unplug every USB stick and external drive (machines happily try to boot from an empty memory stick and give up), and on a desktop, reseat the drive’s power and data cables — a nudged connector produces this exact screen.
If the drive appears by name and its correct size, the hardware is answering and the fault lives in software: a boot order pointing somewhere silly (put the internal drive first and retry — free fix, surprisingly common), boot files corrupted by a power cut or forced shutdown, or a partition map damaged deeply enough that the firmware no longer recognises a system on the disk. All of these leave your files sitting exactly where they were. The careful path: if the data matters, secure it before repairing around it — the drive can be read from a bootable USB or on another machine, or imaged professionally; our missing partition work rebuilds torn maps from a read-only copy. Repair-first is tempting and usually survivable on a healthy drive — but it’s a gamble with no upside if the documents are irreplaceable.
A drive absent from the firmware’s own hardware list — or present as a garbled name or an impossible 0 GB — hasn’t lost its boot files; it has stopped answering as a device. On hard drives that’s failing electronics, mechanics or firmware; on SSDs, almost always the controller. No software can address a drive the computer can’t see, so this branch has exactly one productive move: power down and keep it down. Every hopeful restart spins failing mechanics or re-crashes faulty firmware. On the bench, drives in this state are brought back to a readable condition just long enough to be imaged — the substance of our drive not recognised service — and the files come off the image.
And the warning that belongs in bold whichever branch you’re in: reinstalling Windows is not a recovery method. It manufactures a bootable machine by writing a fresh system across the disk — solving the error and burying the files in a single stroke. Machine first or data first is a real choice; nobody should make it by accident at a setup screen.
It means the machine couldn’t find a working system to start — which is a symptom with several suspects, only one of which is a dead drive. Settings, cables, damaged boot files and a lost partition map all produce the identical message. The BIOS fork below separates the benign majority from the genuine hardware failures in about a minute.
By design, no — it rewrites boot components and leaves your documents alone. Two cautions in practice: on a physically weakening drive, repeated repair passes are heavy reading that accelerates the decline; and a repair that loops endlessly is telling you the problem is deeper than boot files. One attempt is reasonable on a healthy-sounding drive; a campaign of them isn’t.
Both, via different roads. Hard drives usually arrive here through failing mechanics or corrupted sectors in the boot area; SSDs through controller and firmware faults that make the whole drive vanish from the boot list at once. The BIOS test reads the same either way — listed-but-not-booting versus not listed — and the not-listed SSD is very much a lab case, with the data typically intact behind a failed controller.
Free 48-hour diagnostic on the Bristol bench, drives imaged before any repair, written quote before any work — and no fix, no fee on most jobs.