Data Recovery Case File · Formatted & Logical Faults · It Inherited the Wrong History
The Software Recognised an Older Backup and Continued It
Her enquiry describes something being replaced rather than lost. During a backup, "I do not know what happened, but the software replaced all the data I had on this one with the data I had on the previous one, which had broken a few years back. Now all I can find on it is old stuff." Backup applications do not simply add files — they manage a destination, and managing it includes reconciling it against whatever history they believe belongs there.
| Media | External hard drive serving as a backup destination — current backup set displaced by an older set during a scheduled operation; scheduling still active |
| Reported situation | Drive in use as a backup destination · backup operation performed · current content replaced by content from a previously used destination · only historic material now visible · backup schedule not stated as disabled · current content required |
| Fault class | Destination reconciled against an inherited backup set — displaced references with content pending overwrite; continued scheduled operation the principal ongoing risk |
| Equipment used | Drive disconnected and scheduled backups disabled before any assessment · source machine verified as an alternative before any work · post-reconciliation write extent measured against capacity · imaged write-blocked before any reconstruction · displaced structures recovered from surviving copies |
The decode: what managing a destination involves, and the clock on it
The thing to do first, and it is measured in hours: disconnect the drive and turn off the backup schedule. Backup software runs automatically — that is its purpose — and every run writes more to a destination whose previous contents are still physically present. This is not a situation to think about overnight with the drive attached.
Why a backup application writes more than it adds: it maintains a set. That means adding new versions, removing old ones according to a retention policy, and keeping the destination consistent with what it believes the history to be. Deletion is a normal part of its operation, not a malfunction.
What probably happened here: the drive contained a backup set from a previous machine or a previous configuration, and the software recognised it. Applications of this kind offer to inherit an existing set so that history continues rather than starting again — and accepting that, or having it happen automatically, makes the older set the authoritative one. Everything not in it becomes surplus.
Why it looks like a replacement: because functionally it is. The software reconciled the destination against a history that predated her current data, and the current data was not part of that history.
Why the position is nevertheless recoverable: reconciliation removes references. The content itself survives until something writes over it, and a backup operation writes a bounded quantity rather than covering a drive. Provided the schedule is stopped, most of what was displaced is still physically there.
The free check that may end this entirely: the machine being backed up. If her current files are still on the computer, nothing has been lost at all — the destination is a copy, and a damaged copy of intact originals is an inconvenience rather than a loss. That should be established before anything else is commissioned.
What to do afterwards: a fresh destination for a fresh history. Reusing a drive that holds an older backup set is exactly the arrangement that produced this, and starting clean removes the ambiguity the software had to resolve.
On the bench
The drive was disconnected and scheduled backups disabled before any assessment — backup applications running automatically by design, with each execution writing further to a destination whose displaced content remains physically present. The source machine was verified as an alternative before any work. Post-reconciliation write extent was measured against capacity, reconciliation removing references while content survives until overwritten, and displaced structures were recovered from surviving copies.
The outcome
The schedule stopped before any assessment, the source machine verified, and displaced structures recovered from their surviving copies. 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: backup software manages a destination rather than adding to it, and managing includes removing what does not belong to the history it believes in. Your drive held an older set and the software continued that one.
Backup software that replaced your data with older data
Disconnect the drive and turn off the schedule today — backup applications run automatically by design, and every run writes more to a destination whose displaced content is still physically present. Then check the machine being backed up, because if your current files are still there, nothing has actually been lost. What happened is that the drive held a backup set from a previous machine or configuration, the software recognised it and continued that history, and anything outside that history became surplus during reconciliation. That's normal operation rather than a malfunction. Afterwards, start a fresh history on a drive that holds nothing else.
Disconnect it and stop the schedule — call Oxford Data Recovery on 01865 593000; source machine verified first, write extent measured against capacity, displaced structures recovered from their surviving copies.
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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.