Interrupted writes
A power cut, a forced shutdown, or a drive unplugged while Windows was still writing. The most common cause on healthy hardware, and usually confined to whatever was being updated at that moment.
Common
NTFS keeps an entry for every file and folder, recording which clusters hold the contents. This message means it failed to read that entry — not the contents, which are usually still sitting exactly where they were.
NTFS describes every file and folder in a record in its master file table. Lose the ability to read that record and Windows declares corruption, while the contents sit perfectly intact a few clusters away.
chkdsk rewrites the file table to make it internally consistent, and it achieves that by discarding entries it cannot reconcile — which is precisely the information a recovery would have used.The wording points at your file. The fault is almost always in the record describing it.
NTFS keeps a master file table — a database with an entry for every file and folder on the volume, recording the name, the size, the permissions and, critically, which clusters on the disk hold the contents.
When Windows reports that a file or directory is corrupted and unreadable, it has usually failed to read or make sense of that entry, not the file itself. The contents are still sitting in their clusters, untouched. What has broken is the record pointing at them.
Which is why a single damaged entry can make an entire folder tree vanish. Directories are files too, and their contents are lists of what they contain. Damage one directory record and everything beneath it becomes unreachable in a single stroke — while remaining physically present on the disk.
The cause matters because it determines whether this is a quick fix or a warning.
A power cut, a forced shutdown, or a drive unplugged while Windows was still writing. The most common cause on healthy hardware, and usually confined to whatever was being updated at that moment.
The master file table lives in a specific region of the volume. Sectors going bad there produce this error while the rest of the disk reads perfectly — position matters more than quantity.
USB drives and cards, ejected before Windows finished. exFAT and FAT32 have far less redundancy than NTFS, so they tolerate this considerably worse.
If the error spreads to more files over days or weeks, the cause is the disk rather than an event. That is the one where the message is a symptom and not the problem.
The order is the whole point, and almost everyone does it the other way round.
Connect the drive to another machine, or reach the folder by a different path. Sometimes a damaged directory entry is bypassed simply by approaching from another direction.
Whatever is still readable, to a different physical drive, most important first. This is the step that gets skipped, and it is the one that matters.
Reallocated and pending sector counts tell you whether you are dealing with an event or a failing drive. That answer changes everything about what to do next.
And only if SMART is clean. On a healthy drive, chkdsk frequently fixes exactly this — it is what the tool is for.
The single most important thing to understand before running it.
chkdsk exists to make a file system internally consistent. Where it finds a record pointing at clusters that make no sense, it does not attempt to work out what the record should have said — it removes the record and marks the clusters free. The volume afterwards is coherent, which is what it was asked for.
On a healthy drive with one interrupted write, that is a genuine fix and the file you lose was already broken. On a drive with bad sectors under the master file table, it can walk through the damaged region discarding entries as it goes — and each discarded entry is a file or folder that a recovery could have rebuilt from the surviving structure. People arrive here having run chkdsk and finding considerably less than they started with.
NTFS keeps a backup copy of critical MFT records, and a recovery works from those and from the volume’s own redundancy rather than by deleting anything. That is done against a read-only image, so nothing gets worse while it is attempted. Single drives in Manchester are from £300 +VAT after a free 48-hour diagnostic.
That NTFS could not read or interpret the record describing that file, not that the contents are damaged. The data is usually still sitting in its clusters, untouched — what has broken is the entry pointing at it.
Because directories are files too, and their contents are lists of what they hold. Damage one directory record and everything beneath it becomes unreachable at once, while remaining physically present on the disk.
Only after checking SMART and copying off what you can. chkdsk repairs by discarding records it cannot reconcile — on a healthy drive that is a genuine fix, but on a drive with bad sectors it can delete entries a recovery would have rebuilt.
Most often an interrupted write — a power cut, a forced shutdown, a drive unplugged too early. It can also be bad sectors falling under the master file table, which produces the error while the rest of the disk reads perfectly.
Usually, and often completely. NTFS keeps backup copies of critical records, so the structure can be rebuilt from those rather than by deleting anything. Recovery runs against a read-only image, so nothing gets worse while it is attempted.
Watch whether it spreads. A single corrupted folder after a power cut is an event. The same error appearing on more files over days or weeks means the disk is deteriorating — check reallocated and pending sector counts.