Why CHKDSK can’t do what you’re asking.
Windows thinks your drive isn’t formatted and has no data on it. Even the system overhead information telling Windows the location of your data is missing.
That can happen for a variety of reasons.
If you expect there to be data on that drive . . . the news may not be good.
It’s time to break out another tortured metaphor.
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Dealing with RAW drives
A drive appearing as RAW means Windows thinks the drive is unformatted and has no data. If that’s accurate, format the drive. If that’s not accurate, try different connections or machines to try to get it to work. In the worst case — hardware failure — you could be looking at a data recovery service or data loss.
Windows needs disks — internal or external — to have overhead information on them that tells it where your data is stored. The process of setting up that data is called formatting.
Think of it a taking an expanse of bare land and putting streets on it. Nothing more, just streets. You may have seen new housing developments at this stage of construction: no buildings anywhere, but acres and acres of streets.
The streets are the land’s “format”.1 They tell the housing development where it can build houses on the land.
A RAW drive has no format. There are no “streets” for Windows to use to place or locate files.
A RAW drive is the disk equivalent of bare land.
CHKDSK works on streets. To stretch the metaphor, it walks the “streets” on the disk, making sure they’re all properly maintained, that all the houses can be found, that stop signs are where they should be, and that there are no oddities like one-way dead-end streets.
With the “/F” switch, it’ll try to fix the problems it finds — perhaps moving streets around, perhaps connecting up abandoned streets, and otherwise doing the best it can to make sure the disk system of streets is all in good working order.2
But CHKDSK needs the streets to have been started in order for it to do its work. Its job is to check or fix a file system, which means there needs to be a file system to be checked or fixed.
A RAW drive has no file system, and is the equivalent of bare land with no streets at all.
Dealing with a RAW drive
How you deal with a RAW drive depends on your expectations and whether you think the drive has data on it.
If you know the drive is empty, the solution is simple: format it. There are several ways; the most common might be to right-click on the drive in Windows File Explorer and click on Format. Once done, you can run CHKDSK if you like, though there should be nothing for CHKDSK to fix. The streets have been newly paved.
If you believe the drive should have data on it, things get more difficult. My External HDD Shows Not Formatted — But It Has All My Data! goes into more detail, but in summary, you’ll want to:
- Try connecting the drive using a different USB slot.
- Try connecting the drive using a different USB cable.
- Try connecting the drive to a different computer.
- Try moving the drive to a different external enclosure.
- Try data recovery tools on the drive.
- Try a data recovery service, if the information is valuable enough.
Depending on if and how you’re able to get it to work, you can isolate the problem and also decide if it’s time to replace the drive.
I’d be remiss if I didn’t say that getting to that last item in the list means you weren’t backing up. Backing up before problems arise makes any data loss a complete non-issue.
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Footnotes & References
1: As all metaphors must be, this is a gross oversimplification. It doesn’t account for different types of formatting, like FAT32, exFAT, or NTFS. Also, a newly formatted disk is really more like the land having an entrance and nothing else — streets are really built (and removed!) as houses are constructed and destroyed. Fortunately, that’s not really important here.
2: As long as we’re torturing our metaphor, you might consider “/R” the equivalent of looking at every square inch of both the streets and the rest of the land, looking for potholes and land mines, fixing what it can, and setting up “Do Not Go Here” signs for everything it can’t.