How to recover files from a computer that won't boot

A computer that powers on but will not start Windows or macOS usually still has your files reachable. Copy them off by attaching the drive to another computer or by starting the machine from recovery media, and run no repair, reset, reinstall, or erase option until they are safe.

Written by Essential Data RecoveryPublished 2026-09-13Owner-reviewedRevision 1

An open laptop lying back-to-front on a pale oak desk with its side panel screws and a small screwdriver arranged neatly nearby

A computer that powers on but will not start Windows or macOS usually has not lost your files. The machine turns on, and then it sits on a black or blue screen, shows an error, or restarts in a loop. Microsoft's recovery guidance covers exactly this case and tells readers to start with the least disruptive option. The rule that comes before every option on this page: get your files copied off before you repair, reset, reinstall, or erase anything, because Microsoft warns that some recovery options can result in data loss. If the machine shows no sign of power at all, that is a different problem with different steps.^[1]

Laptop with no power at all? That is a different situation

The safety rule first

Stop before you start if the machine begins making new clicking or grinding noises, smells hot, or if the drive fails to appear later when you attach it to another computer. Those symptoms point at a physical fault, and the answer is a recovery lab, not more power cycles. The other half of the rule is about the repair options themselves: do not run a repair, reset, reinstall, or erase before your files are safe. Copying files off a struggling drive is the low-risk half; running recovery options on it is the half Microsoft warns can result in data loss.^[1][2]

Route A: remove the drive and attach it to another computer

The most dependable route is also the most physical: take the storage drive out of the dead computer and attach it to a working one. Kingston, which makes the hardware for this, describes the two options plainly. An enclosure is an external case that houses the drive and connects by USB or Thunderbolt. An adapter is a lightweight converter, such as SATA to USB, that leaves the bare drive exposed. Either has to match the drive's interface, SATA or NVMe, and its form factor, such as 2.5-inch or M.2. Once connected, the drive works like any external drive, which is what lets you copy your files off before anything formats or reuses it.^[2]

Take the drive out and read it from another computer

Unplug the machine, open the panel or bottom cover, and find the storage drive.
Note its interface (SATA or NVMe) and its form factor (such as 2.5-inch or M.2). Those two facts decide what fits.
Get an enclosure (an external case that houses the drive) or an adapter (a SATA-to-USB style converter) that matches both. For a 3.5-inch desktop drive, get one with its own wall power.
Fit the drive in, connect it to a working computer by USB, and wait for it to appear.
Copy your files to that computer or to a second external drive. If the computer offers to format, initialize, or repair the drive, decline: skipping formatting is how you keep the existing data exactly as it is.
If the drive does not appear, or it starts clicking, stop and leave it powered down.

^[2]

A drive that stays invisible on the working computer is the most common dead end here, and it has its own guide. Work through the cable and power checks there before you conclude the drive is gone.^[2]

External drive not detected: what to check next

Route B: start the machine from recovery media

Windows

Two Microsoft facts shape this route on Windows. A recovery drive is not a backup: it restores the device to factory settings, and the recovery media does not include your personal files, so owning one says nothing about your data. And a recovery drive can only be used if it was created while the PC was working. Without one, Microsoft's guidance is to create installation media on another working PC using a USB flash drive of at least 8 GB, and it warns that anything already on that flash drive is deleted. Microsoft's documented routes for a PC that will not start are repair and reset options rather than a file-copy tool, which is why Route A is the more dependable route on Windows.^[3][1][4]

Boot from media on a Windows PC

Find your BitLocker recovery key before you start. If BitLocker is enabled, you need it for most recovery options, and a BitLocker-protected drive attached to another computer will not be readable without it.
On a working PC, create bootable installation media on a USB flash drive with at least 8 GB. Everything on that flash drive is deleted, so pick one that holds nothing you need.
Start the problem PC from that USB media.
If you can see your drive and reach your files from the recovery environment, copy them to an external drive before you run anything else.
If the PC will not boot from the media, or the drive is not visible, stop and go back to Route A.

^[1][3]

Mac

On a Mac the built-in route is stronger. macOS Recovery is the Mac's built-in recovery system, with utilities to reinstall macOS, repair or erase the startup disk, restore from a Time Machine backup, and more, including Disk Utility and Terminal. Getting there depends on the chip. On Apple silicon, press and hold the power button until you see 'Loading startup options', click Options, then Continue. On an Intel Mac, turn it on and immediately hold Command and R until an Apple logo or spinning globe appears. Apple states that reinstalling macOS keeps your files and user settings intact, but erasing the disk is a separate action in the same menu, so the order does not change: copy first.^[5][6]

Copy files from macOS Recovery

Connect an external drive with room for everything you want to keep.
Start the Mac into macOS Recovery using the steps for your chip above.
Use Terminal to copy your files from the startup disk to the external drive. Use Disk Utility only to check the drive if it does not appear, and leave the erase options alone.
Once your files are on the external drive and you have checked them, reinstalling macOS is Apple's documented repair route, and Apple states it keeps files and user settings intact.

^[5][6]

Mac to Mac: target disk mode

Target disk mode (Intel Macs)

Connect the two Macs with a USB, USB-C, or Thunderbolt cable. If either Mac runs macOS 11 or later, it must be a Thunderbolt cable.
If the Mac is off, start it up while pressing and holding the T key.
The Mac appears on the other one as an external hard disk. Copy your files across, then eject it before unplugging anything.

^[7]

Apple silicon Macs do not use the T-key method. For those, Apple routes file transfer to another Mac through starting up in macOS Recovery, which is the route above.^[7]

Do not reinstall or erase yet

On Windows, the last-resort options are the destructive ones. Microsoft states that reinstalling Windows using a recovery drive removes your personal files, apps, and settings, and that a clean install from installation media removes everything from the device. Even the reset option that offers to keep your personal files removes your apps and settings, and it needs a machine that can boot Windows in the first place. None of these belongs before the copy. On macOS, reinstalling keeps files, but the erase options sit next to the repair ones in the same menu, and erasing is not recoverable at home. Get your files off first. The machine can be repaired or reset afterwards.^[1][5]

When the desk routes are done

If the drive is undetected after every check, or it is clicking, the honest answer is that the desk routes are finished. A drive that clicks has a mechanical fault with its own rules, and repeated power-ups work against you. A drive that behaves as if it is dead still has a recovery path, but it runs through a lab, and the cost question is worth reading before you commit to one.^[2]

Clicking hard drive: what the noise means and what to do

Is a dead hard drive recoverable?