Data Recovery Case File · Formatted & Logical Faults · The Figure Is the Evidence
Unallocated of the Right Size Means Nothing Has Claimed It
His enquiry contains a number that settles the diagnosis. A laptop drive partitioned to give a separate area for files, where "this week the drive disappeared completely and the disk manager shows an unallocated area of 737GB. Everything else works perfectly." The missing volume's space is still there, reported at its own size and claimed by nothing — which means the region is intact and only the entry describing it has gone.
| Media | 1TB laptop internal drive carrying multiple partitions — data volume entry lost from the partition table; corresponding region reported as unallocated at its full size; system volume unaffected |
| Reported situation | Laptop drive partitioned with a separate volume for files and folders · that volume disappearing during the current week · disk management reporting unallocated space corresponding to its size · remainder of the machine functioning normally · contents required |
| Fault class | Partition table entry loss with region unclaimed and unwritten — filesystem within the region intact; volume creation the principal ongoing risk |
| Equipment used | Unallocated extent reconciled against the missing volume's size before any conclusion · no volume creation permitted at any point · imaged write-blocked before any reconstruction · filesystem boundaries located by signature within the unclaimed region · partition entry rebuilt and files validated by opening |
The decode: what unallocated means, and why the figure matters
What a partition table is: a small structure at the very start of a drive listing each volume's start point and length. It is the map, not the territory — and it occupies a handful of sectors regardless of how large the drive is.
What losing an entry does: removes the description. The system consults the table, finds no volume claiming that region, and reports the space as unallocated — which is a statement about the map rather than about what is stored there.
Why the size he quotes is the confirming evidence: the unallocated area matches the missing volume. That means the region is exactly where it was, in one piece, with nothing else having taken any of it — no new volume, no expansion of a neighbour, no overlap. The territory is intact and unclaimed.
What is still inside that region: the filesystem, complete, with its own structures and every file. Losing a partition entry does not touch the volume's contents, in the same way that losing a page from an index does not remove a chapter from a book.
Why that makes this among the most recoverable faults here: the filesystem inside the region begins with a recognisable structure at a predictable position. Locating it establishes the volume's true boundaries directly, and the partition entry is rebuilt from what is found rather than guessed at.
Why his other observation matters: everything else works perfectly. The system volume is unaffected, which means the drive is functioning and the fault is confined to one table entry — not a failing device, and not a filesystem problem within the volume.
Now the danger, and it is the most natural thing to click: a disk manager showing unallocated space offers to create a new simple volume in it. That writes fresh filesystem structures over the beginning of the region, which is precisely where the existing filesystem's own structures live. It is presented as the obvious next step.
What else must not happen: no partitioning tools, no repair utilities, and nothing written to that disk. The machine still works, so it can be used — but not for anything that writes to this drive, which on a system drive means using it as little as possible.
On the bench
The unallocated extent was reconciled against the missing volume's size before any conclusion — a partition table listing each volume's start and length in a handful of sectors, so losing an entry removes the description while leaving the region intact, and unallocated space matching the volume's size confirms nothing has claimed or overlapped it. No volume creation was permitted at any point. Filesystem boundaries were located by signature within the unclaimed region.
The outcome
The unallocated extent reconciled against the missing volume, no volume creation permitted, and the partition entry rebuilt from the filesystem found within the region. 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: that figure is the finding. Unallocated space matching your missing volume's size means the region is intact and nothing has claimed it — only the entry describing it has gone.
Partition that vanished leaving unallocated space
Refuse the offer to create a new simple volume — it's the most natural thing to click and it's the one destructive act available, because it writes fresh filesystem structures over the start of the region where your existing ones live. Take encouragement from the figure instead: unallocated space matching the missing volume's size means the region is intact, in one piece, and nothing has claimed or overlapped it. A partition table is a map occupying a handful of sectors, so losing an entry removes the description rather than the contents. Don't run partitioning or repair tools, and write nothing to that disk.
Don't create a new volume — call Oxford Data Recovery on 01865 593000; unallocated extent reconciled against the missing volume, boundaries located by signature, partition entry rebuilt from what is found.
Request a quote online →
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.