Windows CHKDSK – What Does CHKDSK Do Exactly?

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I have attempted to read a bit about chkdsk but I still don't conceptually understand what it does.

From Microsoft: "Creates and displays a status report for a disk based on the file system. Chkdsk also lists and corrects errors on the disk. Used without parameters, chkdsk displays the status of the disk in the current drive."

From Wikipedia: "Displays the file system integrity status of hard disks and floppy disk and can fix logical file system errors."

But this is all extremely vague, and I've not seen a good, concise, clear summary of what is actually going on.

I just ran a chkdsk and got some of the following messages:

Deleting corrupt attribute record
(128, "") from file record segment
120759.

The USA check value, 0x0, at block 0x3
is incorrect. The expected value is
0x63.

The multi-sector header signature in
file 0x3d5b6 is incorrect.

Deleting corrupt file record segment
251333.

Deleting orphan file record segment
251321.

Deleting an index entry from index $O
of file 25.

Deleting index entry P1040158123.JPG in
index $I30 of file 118566.

Is there anywhere I can go to make any sense out of any of these messages? Does it matter at all to an end user? Does it ever delete files or only indices? From the log / output it seems like I had a lot of errors in my disk, but don't know if this is something I should be concerned with or not.

Best Answer

I think that the Microsoft definition is quite good, from your question-

"Creates and displays a status report for a disk based on the file system. Chkdsk also lists and corrects errors on the disk. Used without parameters, chkdsk displays the status of the disk in the current drive."

From what you have shown, your hard drive basically had a bit of corruption, but it looks like chkdsk was able to fix it.

This sort of thing unfortunately happens over time (bad shutdowns / power failures during writes etc.) and it isn't necessarily anything to be concerned about.