It takes one distracted click: the backup drive formatted instead of the new one, the card wiped in-camera before the import ever happened, Windows setup cheerfully erasing the drive that held everything. A quick format is loud but shallow — and shallow is recoverable, if nothing lands on top.
$ ldr diagnose /dev/sdc → Device: SanDisk Extreme 512 GB SD → Status: NOT RECOGNISED — after a wedding → Client: confidential · Wakefield $ ldr engineer-working → Card: forensically cloned → File system: rebuilt on the copy → Photos: 98%+ · full resolution $ ldr verify → ✓ wedding_album — recovered → ✓ every image — verified → ✓ couple — relieved
A quick format — the default nearly everywhere — writes a fresh, empty file system: a new index at the front of the drive, your data untouched behind it. Recovery reads past the new emptiness, finds the old structures or carves the files directly, and typically returns the bulk of what was there. A full format on modern Windows is graver — it zeroes as it goes — and honesty requires saying so: fully-formatted regions are gone, and the diagnostic will map exactly where the zeroing stopped if it was interrupted. The universal instruction either way: write nothing to the drive — and if the format was step one of ‘reinstalling Windows’, do not proceed to step two on that disk.
We see the same four stories on repeat. The two-drive mix-up (D: intended, C: clicked — drive letters betray everyone eventually); the OS reinstall that formatted the data partition it was supposed to sail past; the ‘initialize disk’ prompt obeyed when an old drive’s partition table hiccupped — formatting a drive that was merely confused; and the in-camera format executed one import too early. Each leaves a different signature and each recovers differently — which folders, which file types, with or without names — and the free diagnostic tells you precisely which story yours will be before a penny moves.
If it was a quick format and the drive was stopped there, then usually yes, and largely so. The new empty index sits in front of your old data like fresh paint on a full filing cabinet. Odds decay only with new writes, so the drive's job now is to sit powered off.
Harder, and we’ll be honest about it: a reinstall formats the partition and then writes gigabytes of operating system across the front of the drive. What Windows didn't reach — typically the bulk of a larger drive — remains recoverable, often nameless but intact. The diagnostic maps the overwrite and lists survivors for free.
Each new photo may have landed on an old one — but cards are large and shoots are small, so partial recovery is the likely verdict, weighted against whatever the new session didn't touch. Stop shooting on it now and the diagnostic will count what's left.