How to fix
RAW file system errors
on Windows

The file system on my drive is RAW now, and CHKDSK says it is not available.

A RAW file system means Windows can no longer read the structure that tells it how files are stored on the drive. The partition may still exist, and the disk may still spin up or show a drive letter, but the operating system treats it as unreadable because the file system metadata is missing, damaged, or no longer recognizable. In practice, that is why an otherwise familiar disk suddenly turns inaccessible in File Explorer, why opening it can trigger a formatting prompt, and why CHKDSK refuses to run when the file system is already unreadable.

The visible symptom usually arrives at the worst possible moment. A drive that worked normally may begin showing the message The type of the file system is RAW. CHKDSK is not available for RAW drives. when you try to check or repair it. In other cases, Windows instead asks whether you want to format the disk before you can use it. That prompt is not a harmless warning in this situation, because formatting makes the drive usable again only by assigning a new file system and erasing the existing one. When the drive contains important files, the immediate problem is not just access, but the risk of permanent data loss if the wrong repair path is chosen first.

RAW status can appear on internal hard drives, external hard drives, USB flash drives, SSDs, and partitions that were previously healthy. The error is often discovered after a failed boot, an interrupted copy process, a power outage, an improper shutdown, or a formatting failure. Virus activity is another stated cause, and the result is the same: Windows can no longer interpret the file system well enough to mount the volume normally. Once that happens, the drive may still be visible in Disk Management, but it will not behave like a regular NTFS, FAT32, or exFAT volume.

The real problem is that RAW is not a normal file system state that Windows can simply “read through.” It is a sign that the volume header, partition metadata, or file allocation structures are damaged enough that the operating system cannot identify the format. That is why the error is closely tied to CHKDSK failure. CHKDSK is designed to examine and repair recognized file systems, so when the file system itself is no longer recognized, the tool has no structure to work on. The refusal message is therefore a symptom of the deeper problem, not the cause of it.

One common mechanism is metadata corruption. File systems depend on internal records that map where files begin, where directories point, and how clusters are linked together. If those records are damaged, the partition can still exist physically but lose the logical map that Windows needs to interpret stored data. In that state, even a disk that contains most of its original content may appear empty or unreadable because the operating system cannot safely traverse the damaged structures.

Another cause is incomplete or failed formatting. The source material notes that a RAW drive may simply not have been formatted with a file system, or that formatting may have failed partway through. In both cases, Windows sees a volume without a complete, recognizable file system signature. A partially written format can leave the disk in an especially confusing state, because some structures may exist while others do not, which is enough to block normal mounting while still preventing repair utilities from treating it as healthy.

Power interruption and improper shutdown create a different kind of damage. When the computer loses power during a write operation, file system metadata may be left in an inconsistent state. Journaling can reduce the risk on some file systems, but it cannot guarantee recovery if critical records are overwritten or left incomplete. The next time Windows reads the volume, it may find structures that do not match one another, which can be severe enough to push the partition into RAW status rather than offer a simple repair.

Virus attacks can also corrupt the file system layer directly or indirectly. Malicious activity may alter boot records, damage partition tables, or disrupt files that the file system relies on to stay coherent. The source material names virus attacks among the reasons RAW errors appear, and that matters because a drive can fail not only from hardware-like interruptions, but also from software-level tampering that leaves Windows unable to trust the volume’s layout.

A related cause is plain recognition failure. The drive may still have a file system, but Windows cannot identify it because the current format is unfamiliar, the metadata is damaged, or the file system identifier is unreadable. In that condition, the disk is present but effectively opaque. The operating system knows the storage exists, yet it cannot translate the contents into folders and files because the code that describes the layout is no longer dependable.

That is why RAW errors matter beyond the single warning message. A volume in this state is not just inconvenient to open; it is disconnected from the normal storage workflow that Windows expects. Programs cannot read from it normally, file copies stop, and repair tools that depend on a recognized file system lose their usual entry point. The repair choice therefore has to start with preserving whatever data remains readable before any formatting step recreates the volume.

Windows treats file systems as the layer that makes storage usable, whether the volume is NTFS, FAT32, or exFAT. Under normal conditions, the file system organizes the disk, records file locations, and allows the operating system to mount the volume for direct use. When that layer fails, the disk can still be physically present but logically unavailable, which is why the partition may show up in the system without opening correctly.

The link to CHKDSK is central here. CHKDSK is built to check and repair recognized file systems, including file structure issues and some disk errors. It cannot do that work if the file system is already RAW, because there is no valid file system map to repair. That limitation explains the error message directly and also explains why formatting is often presented as the route to make the drive usable again. Formatting creates a fresh file system, but it does so by replacing the old one.

For that reason, the practical order of recovery is clear: get the data off first if the files matter, then rebuild the volume into a usable Windows-compatible file system. The source material also points to source and source as references for recovery and formatting-related workflows, and it emphasizes that data recovery services are available when the drive cannot be safely repaired by hand. Here are 3 solutions to fix The type of the file system is RAW. CHKDSK is not available for RAW drives.

Fix 1. Recover files before making any file system changes

This method protects the data that is still readable in the RAW volume before formatting or repair replaces the damaged structure.

• Open the recovery tool and select the RAW partition from the drive list.
• Start a full scan if the partition has lost its label.
• Use the search box or file type filters to narrow the scan results.
• Preview the found files and confirm the ones you need.
• Select the files and click Recover.
• Save the recovered data to another internal drive, external drive, or cloud location.

Fix 2. Format the RAW partition to NTFS, FAT32, or exFAT

Formatting replaces the unreadable file system with a fresh one, which is the direct way to make the volume usable again after data is safe.

• Open This PC.
• Right-click the RAW partition and choose Format.
• Select NTFS, FAT32, or exFAT as the file system.
• Review the prompt that warns the disk will be erased.
• Click Start.
• Confirm with Yes when Windows asks to begin formatting.

Fix 3. Recreate the file system with Diskpart

Diskpart can rebuild the partition format from the command line when the standard format dialog is not the preferred path.

• Press Windows + R.
• Type diskpart and press Enter.
• Type list volume and press Enter.
• Type select volume X and replace X with the RAW volume number.
• Type format fs=ntfs quick or format fs=fat32 quick.
• Type exit when the format finishes.

Šaltiniai: easeus.com/resource/chkdsk-reports-raw.html