Windows · critical · Hardware, drivers & peripherals

"You need to format the disk before you can use it"

The partition table or filesystem header is unreadable, so Windows sees an unformatted volume. The data is usually still there.

What you see

A USB stick, memory card or external drive prompts to be formatted every time it is connected. Disk Management shows the volume as RAW.

What is actually wrong

Almost always an interrupted write — removed while writing, or a power loss. Occasionally a failing controller in the enclosure rather than the drive itself.

Codes and articles

You need to format the diskRAW0x8007045DThe volume does not contain a recognized file system

Fixes (2)

Image it first, then attempt repair on the copy

Elevated PowerShell, plus a drive with space1–3 hourslow riskreversible

The data matters. Do not click Format, and do not run chkdsk on the original — both can turn a recoverable volume into an unrecoverable one.

Stop using the device now. Every further write reduces what can be recovered.

Identify the disk number without mounting or writing to it.

PowerShell

Get-Disk | Format-Table Number,FriendlyName,OperationalStatus,PartitionStyle,SizeGet-Partition | Format-Table DiskNumber,PartitionNumber,DriveLetter,Size,Type

Take a full sector-by-sector image to a file on a healthy drive, using a recovery tool that reads past errors — ddrescue on a Linux live USB, or a Windows imaging tool with a bad-sector retry option.
Every repair attempt from here on runs against the image. If a repair makes things worse — which it can — the original is untouched and you get another go. Skipping this step is how recoverable data gets lost.
Run file-carving recovery against the image with a tool such as PhotoRec or R-Studio, writing recovered files to a third location.
Only once the data is safely recovered and verified, format the original device.

Confirm it workedThe recovered files open correctly from their new location — check several, not one.

If you need to undo itThe original device is untouched throughout, which is the point of the whole procedure.

Reformat and check whether the device is worth keeping

Elevated PowerShell30 minuteshigh risknot reversible

There is nothing on it you need. This destroys the contents.

Confirm the disk number twice. Formatting the wrong disk is not reversible.
PowerShell
```
Get-Disk | Format-Table Number,FriendlyName,Size,BusType
```

Clear and repartition it.

PowerShell

Clear-Disk -Number 3 -RemoveData -Confirm:$falseInitialize-Disk -Number 3 -PartitionStyle MBRNew-Partition -DiskNumber 3 -UseMaximumSize -AssignDriveLetter |  Format-Volume -FileSystem exFAT -NewFileSystemLabel 'DATA' -Confirm:$false

exFAT rather than NTFS for removable media — it is readable on macOS and most devices, and it does not carry the NTFS journal that makes an interrupted removal so damaging in the first place.

Do a full read/write test before trusting it with anything. A device that went RAW once from a clean removal will do it again.
PowerShell
```
Get-Volume -DriveLetter E | Format-List DriveLetter,FileSystem,HealthStatus,SizeRemaining
```
If it fails again within days, replace it — a failing flash controller cannot be repaired.

Confirm it workedA large file copies on and reads back with a matching hash.

PowerShell

Get-FileHash E:\test.bin -Algorithm SHA256

If you need to undo itNone. The contents are gone once Clear-Disk runs.

Where this stops. This write-up was written and checked by hand. It says what each step changes, how to confirm it worked and how to reverse it, and anything destructive is flagged before you reach it. If it does not match what your machine is doing, search the Support Centre for the exact code or message — and when something needs a person, get in touch.