No One Reads Beneath an Overwrite

The decode

A reinstall does not erase a drive; the years afterwards do. Installing a fresh system overwrites some regions and marks the rest as free. Every day of use since has been quietly claiming that free space. A file from before the reinstall survives only where nothing has landed on its sectors in all the time between — and each passing year shortens those odds.

The tools he bought were not failing; they were reporting. Commercial recovery software carves free space for recognisable file signatures. That they recovered "quite a bit" but never the wallet means the search worked and the target was not in the reachable remainder — or survives only in fragments too small to announce themselves. More tools of the same kind repeat the same sweep.

"How deep" deserves a straight answer. There is no deeper layer beneath an overwritten sector where the old bytes wait. Once new data is written, the previous contents are gone as a matter of physics, and any service advertising recovery from beneath an overwrite is selling something that does not exist. What a laboratory legitimately adds is completeness — a byte-level sweep of every unallocated region on a write-blocked image, targeted at the wallet file's specific internal signatures rather than generic types — and honesty about what the sweep shows.

The kind of drive decides how much hope is rational. If this MacBook has a hard disk, overwritten means overwritten but untouched regions genuinely persist for years, and a targeted sweep has a real if modest chance. If it is a solid-state drive, the housekeeping that keeps SSDs fast erases discarded space in the background — usually within days of the reinstall, years ago. That distinction is established in the first minutes of assessment and shapes everything said after.

The most promising search may not be on this drive at all. A wallet file is small and travels: old external backups, a Time Machine disk used even once, a previous computer, an email sent to oneself. Sideways is where files lost to time most often turn up — and it costs nothing to look there while the sweep runs.

On success rates, the defensible number is conditional. Across this class of work, recoveries come from surviving unallocated fragments or from lateral copies; they do not come from beneath overwrites. Anyone quoting a confident blanket percentage for a years-old deletion is quoting marketing, not evidence.

On the bench

The drive was imaged under a hardware write-blocker and the medium identified first, since disk and SSD set different expectations. The image was taken under a Tableau hardware write-blocker, its unallocated space swept end to end in X-Ways Forensics for the wallet file's database signature values, candidate fragments hex-verified rather than trusted by name and cross-checked with OSForensics, and the result reported against the whole sweep — including, where that is the truth, that the sectors in question have been reused and the file no longer exists to find.

The outcome

Write-blocked image, medium established, full unallocated sweep for the file's own signatures, hex-verified findings, and a parallel checklist of lateral sources. Free assessment, one fixed written figure including VAT; where recovery is not possible, nothing is charged. The decode: depth is not the variable — survival is. We search everything that still exists and tell you plainly which category your file fell into, because a paid-for maybe is worse than an honest no.

Our case files are written up from genuine enquiries our lab has handled for customers across Sheffield and South Yorkshire, anonymised to protect client confidentiality. Each one describes the diagnostic and recovery approach our engineers apply to that fault, using the equipment listed.