Data Recovery Case File · Desktop Externals & Aging Drives · Some Files, Not Others
Varied Errors Across Different Files Describe Damage in Patches
His enquiry contains a detail that shapes the whole approach. An external drive that "appears in the list in the file browser, but when trying to view files it comes up with various errors." Various is the operative word: consistent failure across everything would suggest one cause, while errors that differ by file indicate the drive reading some regions and not others — which means part of it is fine.
| Media | External hard drive — enumerating and listing normally, returning differing errors on attempts to open files; content partially accessible |
| Reported situation | External drive appearing in the file browser · directory listing available · attempts to open files returning errors · errors differing between files · content required |
| Fault class | Regional read failure with structures intact — directory readable and content regions variably returning; degradation patchy rather than general |
| Equipment used | Varied errors interpreted as patchy regional failure rather than a single cause · drive removed from ordinary use before capture · imaged write-blocked under strict per-sector timeouts with healthy regions taken first · marginal regions revisited across later passes · recovered files validated by opening |
The decode: what varied errors indicate, and why browsing makes it worse
Why the listing working matters: the structures describing the drive's contents are readable. The device enumerates, the filesystem is intact enough to enumerate folders, and the fault is not in the drive's ability to function — it is in returning particular content.
Why differing errors are more informative than identical ones: a single repeated error suggests one cause affecting everything. Different errors on different files means different outcomes for different regions, which is the signature of patchy degradation rather than a general fault.
What that implies about the drive: some areas return data normally and some do not. Files sitting entirely in healthy regions should open perfectly, files spanning damaged ones fail, and which is which depends only on where each happens to sit.
Why that is comparatively hopeful: a substantial proportion of the content is likely to be readable right now. The question is how much and which, and that is established by capturing rather than by testing.
Why browsing is the wrong way to find out: opening files one at a time to see which work is a slow survey that costs the resource it is measuring. Every failed attempt is retry cycles on a degrading drive, and the information gained is recoverable far more cheaply from an image.
Why an ordinary copy also fails here: it proceeds in folder order and stalls on the first difficult file. Hours are spent on one unreadable item while healthy material further down is never reached, which is the worst allocation of a drive's remaining life.
What is done instead: imaging under strict per-sector timeouts, so no region absorbs the available time. Healthy areas are captured first at full speed while the drive is at its best, securing the bulk before anything difficult is attempted.
Why marginal regions are then revisited: a region that fails on one attempt frequently returns on another. Patient repetition across multiple passes recovers material a single pass cannot, and it happens after the healthy content is already safe.
What patchy degradation usually indicates about cause: accumulated surface deterioration rather than a discrete event. Drives reallocate failing regions throughout their lives until the reserve is exhausted, after which failures become visible — which is a gradual process rather than something that happened.
What must not happen: no further browsing, no consistency check, and no repair prompts accepted. A check on a drive with unreadable regions discards references to content that is still there.
On the bench
Varied errors were interpreted as patchy regional failure rather than a single cause — an available directory listing establishing enumeration and readable structures, so the fault lies in returning particular content, while differing outcomes across files indicate differing region conditions rather than one general fault. Files held entirely within healthy regions open normally. Imaging ran write-blocked under strict per-sector timeouts with healthy regions taken first and marginal regions revisited across later passes.
The outcome
The varied errors read as patchy regional failure, the drive removed from use, and healthy regions captured first under capped timeouts. Free assessment, one fixed written figure including VAT; where a drive has to be opened, 50% of parts and labour is payable upfront with the balance only on success — otherwise no recovery, no fee. The decode: various is the useful word. One repeated error would suggest a single cause, but errors differing by file mean some regions return data and some do not — so a substantial part of your drive is fine.
A drive that lists files and errors on some of them
Stop opening files to find out which work — that survey costs the exact resource it's measuring, since every failed attempt is retry cycles on a degrading drive. Read the varied errors as encouraging: one repeated error would point at a single cause, but different errors on different files means some regions return data and some don't, so files sitting entirely in healthy areas are fine. Don't run an ordinary copy either, since it proceeds in folder order and stalls on the first bad file while healthy material further down is never reached. And refuse any consistency check.
Stop testing them — call Easy Data Recovery on 028 9002 0144; varied errors read as patchy regional failure, imaged under capped timeouts with healthy regions first, marginal areas revisited across passes.
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Our case files are drawn from genuine enquiries received by our laboratory over the past ten years, anonymised to protect client confidentiality. Each one describes the diagnostic and recovery procedure our engineers apply to that fault, using the equipment listed.