What is this Raw File System

Sometimes a damaged volume may look like it lost its file system and CHKDSK tool will complain that file system is raw

The type of the file system is RAW.

this is a curious issue as seen here


what the hell is a RAW file system?—


what the hell is a RAW file system?—is easy enough to answer. It's simply a disk partition that has not been

formatted with an NT file system, neither FAT nor NTFS.


so what is this raw or as said raw file system, it is nothing but a system supplied file system driver that is the

"last resort" for all I/O requests requiring file system support. When the I/O manager calls active file systems

 to mount a volume, RAW is always called last because it supports all disk and tape media.

However, RAW supplies very primitive file handling capabilities. That is, it does not impose any on-disk file

structure or metadata structures for the information about the media; it simply allows read/write access

to the logical blocks on the physical disk. For example, it treats the whole disk as a single file and supplies

physical-disk-level access to the disk.


If a device is being driven in raw mode, it has no function driver and no upper or lower-level filter drivers.

All raw-mode I/O is done by the bus driver and optional bus filter drivers.


Note, however, that a bus driver does not handle read and write requests for the devices on its bus.

Read and write requests to a device are handled by the device's function driver only. Only if the device

is being used in raw mode does the parent bus driver handle reads and writes for the device.

ok the above extract is from DDK ...now lets see where can i see this happening





here you see that it is for rawtape, rawcdrom, rawdisk (I am using device and driver explorer here )





so how can i reproduce this issue--raw file system reported by chkdsk --we can use dskprobe from http://technet2.microsoft.com/WindowsServer/en/library/006902f1-bae9-4055-9ad2-123ea19006b71033.mspx 

and repro this issue ( please do not try this on a production or home machine -you may loose data)

There are two places where we store file system information as seen below

1 MBR partition Table

2 Volumes' boot sector

When the file system information provided on these 2 sectors of disk is not good you may see chkdsk reporting raw file

system (though the data is still there)








A Raw volume is a volume that was never formatted and does not contain a File System



so just to play i did same on my test machine and removed OEM ID string on D drives Volume boot sector and yes this is

my production machine containing lots of data, Now when i try to access D drive it asks do you want to format it...

..Of course NOT

As if we format we will lose all the data on D drive.

I tried running Chkdsk and you can see results below. It says, type of File System is raw. Chkdsk is not available for raw drives.

I reversed my changes using dskprobe again (added NTFS IN OEM ID string) and Yes my data is back and D drive is  accessible.




Gaurav Anand

This posting is provided "AS IS" with no warranties, and confers no rights.

Comments (32)

  1. hi:

    I have problems like you had with the drive file system not recognized. I tried to

    run dskprobe but I can’t find it on my system. I have a win 2000 pro with sp4 and

    dskprobe is not there. Is it possible that you send me a copy of it with any other

    file required to run it. I have a lot of data on my disk and I don’t want to loose it.

    Another thing, this ‘device and drivers explorer’ what is it and how can I get a

    copy of it?

    Please, mail me some info. my e-mail is     sgt_fig1@hotmail.com     I promise that

    NOTHING illegal will take place.

    Thank you for any help that you may give me.


  2. cathy says:

    I have a problem with my disk. Same problem as yours, but i can’t find the diskprobe, can you gave an idea, where i can find those files. and also the device and drivers explorer. what is it? how can i get thoses file? can you send me those files. thanks! catherinerodil@yahoo.com

  3. mustafa says:

    Hi I have a problem of flash disk that says its RAW file system and i cannot format it plz help me.

  4. Me says:

    Looks like that the dskprobe is only available in Windows XP and Windows Server 2003. I hope it works on xp because i can try it on another computer. If only on 2003 im el’screwdo.

  5. tsFox says:

    And the DeviceTree

    i downloaded from here


    you have to register

  6. glen says:

    I had trouble finding Diskprobe (even online from Microsoft).  After some research and some thinking, I decided to search my computer for a copy.  I found it on the new CD that I made when I slipsreamed Windows Service Pack 3 onto my original Windows XP CD.  You can check your cd for a copy.  It may be on older versions as well.  Look under Support Tools.

  7. stephen says:

    i use a netac 2gb pendrive and it just stoped workin. i tried formatin it and it said can not cos it was  a raw system

  8. paul says:

    I have the same problem and i have a pc with SP2. i cant find any of those programs. i have that RAW problem with a 500GB Segate and i have over 100GB of important files please can you explain how to get them back without deleting the file on there because the above is kind of hard to understand. thx

  9. careless00045@yahoo.com says:

    i just wanna take my files back, when ever i try to explore my partition, it says do u want to format it  now, and yes its RAW file system,

    i just wanna take backup for my files and i don’t care about the hard disk.. please help. e-mail me there Careless00045@yahoo.com thanx alot.  

  10. gigaman45@gmail.com says:

    Yeah I’m trying install a webcam of mine and the installation CD says File System: RAW meaning it can’t be read.

    It said Windows cannot read the disk.

    Can somebody help me?

  11. ankit5 says:

    i have to donelod to rowfilesystem

  12. Kevin says:

    Hey, my 500gb seagate hard drive is a RAW file as well. I try and reformat the drive, but it won’t allow me to do so. I can view the files as a read only file on Macs but not on PC. On PC it won’t allow me to do anything to the drive, not even change some permissions. If anyone has a solution e-mail me at iamfoxy2004@hotmail.com Thanks.


  13. Austin says:

    ok well.. these tools would be nice if i knew exactly where to find the right sectors and what not..

    my laptop hdd is the one with the problem.. it boots into windows just fine.. but when i try to schedule the chkdsk through the drive properties it just closes on me and doesnt ask to schedule.. so i type it in the cmd prompt. it asked me there so i say yes of course..

    when i restart it to do the chkdsk it says its RAW and whatnot..

    ive been looking all over for the solution.. i even tried running ZAR and still no luck.

    plz help.. ?  my email is austalapasta@gmail.com

  14. simon tusiime says:

    what can be done to solve the problem of RAW filling system

  15. alicia says:

    I bought dvd-r memorex, to make a recovery disk in windows xp home edition, but the dvds are o space available with a raw system, i tried to format them but couldn’t, can some one help me???

  16. Sammc says:

    I was given a RAW message for my 40GB 2.O Hard drive (MAXTOR 6L040J2)

    I was denied access to Drive Z:

    I shut down my Computer.

    Signed in as administrator  gave permission for everything removed all passowords.

    I am using XP for the PC.  I wanted to use external drive to transfer files to Notebook with VISTA

    Restarted computer.

    At command prompt entered "Convert Z: f/NTFS"

    This time, message stated the Z was NTFS

    Entered  Chkdsk/f Z:

    System processed command; fixed errors on several levels — mirror etc.

    Entered Dir Z:

    All files restored.

    Have tested disk by adding and retreiving files.

    Thank  you,


  17. Sammc says:

    Also, when I first attempted to save files to external USB drive from VISTA notebook, received message than I could not save files, contact administrator.

    I selected the external drive’s properties and changed to  "Sharing" with "Everyone" having full rights because  I am the only one using the notebook. I can change it back.

    This change allowed me to have full access to the drive without being concerned about whether I am logged in as adminstrator.

  18. Wesley says:

    I have a flash drive that windows explorer sees as RAW … yet most everything else, including chkdsk, see it as FAT32 (which it is) … can someone please tell me how I can knock some sense back into win-explorer, and force it to recognize the drive for what it really is?

  19. Assertive says:

    Hi, can you help, I am trying to format my ipod mp3 player.  The command will just run upto about 99.9% and give this error message,

    "Windows could not complete the format process"

    What am I suppose to do; the file system is being told as raw plus it is infected by viruses.  Avast failed to remove the virus

  20. ali says:


    Try this:

    Mount the drive as a slave inside the computer and see if you can repair the partition table:

    Download the Windows version of TestDisk.

    Unzip the downloaded file to your C: drive and open C:testdisk-6.8win > double click " testdisk_win" (the program doesn't have to installed).

    A. At the first window select “No Log” and press the <Enter> key.

    B. Select what drive to analyse, choose “Proceed” and <Enter>.

    C. Select partition type – Intel if it’s a PC.

    D. Select “Analyse” then <Enter>. The drive/partition will be analysed.

    E. Select “Proceed” at the next screen, then <Enter>.

    F. Press “Y” if the partitions were created under Vista – “N” if not.

    G. TestDisk should say “Structure OK”. Choose the drive/partition to fix. Then press <Enter>.

    H. Select “Write” and press <Enter>.

    I. Press “Y”.

    J. Press <Enter> and close TestDisk. Reboot the computer.

    From: http://www.techsupportforum.com/…/192014-my-file-system-now-raw-help.html

  21. John says:

    I went and downloaded the TestDisk and the PhotoRec software from the link http://www.cgsecurity.org/…/TestDisk_Download and found that the PhotoRec software works great! and I mean GREAT! Thanks so much for the link. I will find someway to donate. Thanks again.

  22. Moe Badderman says:

    Three words of advice: Zero Assumption Recovery.


  23. Jfaun says:

    I have a 880 gb Seagate usb hard drive. I have plenty valuable files on it. Now I can not access the files, but I can see the file directory in Windows explorer most of time, even though Windows explorer takes a lengthy time to discover it. When I try to open a file, computer takes a long time to tell me the request can not perform because of I/O error. I have tried on various computers and cables, all the dame.  I use error checking from drive property, it takes me no where. In the Disk manager, the drive sometimes showing healthy, the other times showing unallocated. In the command line, chdsk shows the drive is RAW. I used Testdisk, PhotoRec, ZAR,EasyUs, all of them dont work. Can anyone help please?

  24. janey says:

    with the help of diagram explain what actually happen to the computer system when the user type a raw data such as 2*3(67-4) ?

  25. Diana says:


    try this download.cnet.com/…/3000-2248_4-75279786.html

    it will hel you to recover data from your partition

  26. sam says:

    my 8 gb usb showning raw fil system

    i dont need data i need my usb back to wrok ……?

    plz help

  27. Gimg says:

    When raw drive comes to a hard disk or memory card, the file system shows raw and it would notice you the drive is not formatted. And you will see your data to be 0 byte.

    Converting raw to ntfs or fat is possible with testdisk for free.

    Tips, if you want to recover your data, you should use free tool like icare data recovery free edition to free restore files in raw drive.

  28. Balinda Markbeth says:

    Actually, in some degree, RAW drive problem is not a serious problem as log as you take the right steps.

    <1>. Stop writing anything new on this thumb drive immediately in case of overwriting the original data, which can cause permanent data loss.

    <2>. Download a recovery program on your computer and run it. In my experience, you can apply a free and reliable recovery program, which I have tried to retrieve inaccessible files from my RAW drive. It doesn’t let me down. Now I have regained these files and made my RAW drive workable as before. You can read about it here: http://www.squidoo.com/how-to-make-a-raw-drive-to-work-again-without-losing-data

    <3>. Preview your recovered files to see whether they are recovered rightly.

    <4>. Save the recovered files in a different drive in case of recovery failure.

    <5>. Never forget to format your drive to make it usable again after the recovery stuff.

    <6>. Back up your important files as possible as you can in the future.

  29. Tim says:

    To solve the raw file system problem, you can use M3 RAW to NTFS Converter and M3 RAW to FAT32 Converter to change you RAW file system to its previous file system without data loss.

  30. CorynneSon0 says:

    Hello, thanks for your nice post! In fact, last time, when my external hard disk showed as RAW file system in Disk Management, your description really helped me a lot. Honestly, this drive just weirdly asked me to format whenever I tried to access my left
    files inside at first. So, in order to figure out what was going on there, I immediately checked the properties and related information there. And then, found the file system of this hard disk was turned into RAW. It nearly drove me crazy when I realized all
    my school documents inside were lost. However, fortunately, after trying some data recovery solutions online, I did rescued most of my files back.

    Thanks for your useful clues.
    Read more here: http://www.icare-recovery.com/raw-drive.html

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