Mar
12
2012

Filter Drivers – Removable Media as Fixed Disk in Windows

USB Flash Drives are seen as Removable Media and USB Hard Disks are seen as fixed drives in Windows.Due to this USB Flash Drives cannot be partitioned using the inbuilt Disk Management Utility.Also all the partitions of a partitioned USB Flash Drive cannot be accessed simultaneously.However they can be partitioned and accessed one by one using Bootice.

Important Facts about Windows and USB Storage Devices

  1. USB Flash Drives cannot be partitioned using Windows Disk Management
  2. USB Hard Disks can be partitioned using Windows Disk Management
  3. Third Party Tools can partition a USB Flash Drive. But all partitions will not be visible.Only the first partition will be visible
  4. All partitions of a USB Flash Drive are visible in Linux

However a USB Flash Drive can be disguised as a USB Hard Disk using Filter drivers.This way a USB Flash Drive can be partitioned using the inbuilt Disk Management Tool(diskmgmt.msc) and all the partitions of the USB Flash Drive can be accessed simultaneously in Windows Explorer.

A filter driver is a Microsoft Windows driver that adds value to peripheral devices or supports a specialized device in the personal computer. It is a driver/program/module that is inserted into the existing driver stack to perform some specific function.

In this case Filter Drivers make USB Flash Drives (Removable media) appear as fixed drives in Windows.

There are three filter drivers which can be used for this purpose.The pros and cons of each driver will be discussed

  1. Hitachi Microdrive Filter Driver – cfadisk.sys
  2. Anton Bassov – Dummydisk.sys
  3. Karyonix – diskmod.sys

Hitachi Microdrive Filter Driver – cfadisk.sys

Video Tutorial for installing Hitachi Microdrive Filter Driver

Install Hitachi Microdrive Filter Driver

  1. Download cfadisk.zip.I have modified the cfadisk.inf to work with all USB Flash Drives using USBSTOR\GenDisk as posted by cdob@msfn
  2. Open Device manager (devmgmt.msc) and check for your USB drive in “Disk Drives”.
  3. Right click on the entry for your drive and select option to update driver.
  4. Don’t use windows update
  5. Browse my Computer for driver software – Locate and install driver software manually
  6. Let me pick from a list of device drivers on my computer
  7. Have disk
  8. Browse to location of downloaded cfadisk.inf
  9. Update the driver

Your USB Flash Drive will be immediately detected as a Fixed Disk and you can then partition or access your partitions on your USB Flash Drive.

Uninstall Hitachi Microdrive Filter Driver

Follow steps 1 to 7.Then select Disk drive and update.Your USB Flash Drive will recognized correctly as Removable Media.It will no longer be disguised as a Fixed Drive.

Features of Hitachi Microdrive Filter Driver

  • No Restart required.
  • Only Specific USB Flash Drive is disguised as a Fixed Drive.Other USB Flash Drives are still seen as Removable Media
  • Switching between Removable and Fixed modes can be done without restart by installing or uninstalling the filter driver
  • Tedious procedure for installation and uninstallation

Anton Bassov – Dummydisk.sys

Install Dummydisk.sys

  1. Download dummydisk.zip and extract the package
  2. Run INSTALL_DUMMY.cmd
  3. Reboot the computer

Uninstall Dummydisk.sys

Run REMOVE_DUMMY.cmd and reboot

Features

  • Easy to install and uninstall
  • Disguises all USB Flash Drives as Fixed Drives
  • Restart is required after install or uninstall of the driver
  • Driver once started cannot be stopped
  • Switching between Removable Mode and Fixed Mode requires a reboot

Karyonix – diskmod.sys

Diskmod.sys was originally written to allow pagefile.sys to reside in a USB Hard Disk.However its other features include disguising UFDs as HDDs and HDDs as UFDs.

Install and use diskmod.sys

Update: For Windows 7 64 bit you need to enable TESTSIGNING before installing Diskmod.
Run command prompt as admin and execute this command

Bcdedit.exe -set TESTSIGNING ON
  1. Download and extract diskmod-0.0.2.2.zip
  2. Right Click on diskmod.inf – Install
  3. Run UFDasHDD.bat and replug your USB Flash Drive to make it appear as Fixed Disk
  4. Run UFDNormal.bat and replug your USB Flash Drive to make it appear normally as Removable Media
  5. Run USBHDDasUFD.bat and replug your USB Hard Disk to make it appear as Removable Media
  6. Run USBHDDnormal.bat and replug your USB Hard Disk to make it appear normally as Fixed Disk.

Features

  • USB Flash Drives can be disguised as USB HDDs
  • USB HDDs can be disguised as USB Flash Drives.This feature was missing in cfadisk.sys and dummydisk.sys
  • Easy to install.No Reboot required
  • Very easy to switch between Removable and Fixed modes for both USB Flash Drives and USB HDDs.You just have to change a value in the registry and replug your USB Device
  • All connected USB Devices are affected.Karyonix’s post at reboot.pro mentions that individual USB Devices can be targetted without affecting the other connected USB Devices.However I have not been able to get that setting working

Diskmod is one of the best filter drivers available for disguising a UFD as a USB HDD or vice versa.

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About the Author: Bharat Balegere

Bharat Balegere is a 23 year old blogger from Bengaluru. He is a technology enthusiast and loves tinkering with computers and usb drives.

25 Comments + Add Comment

  • Great stuff…clearest explanation I have seen of this procedure yet. Will this work for SD/MMC cards as well?

    Cheers.

    • I haven’t tried this for SD/MMC cards.I will try and let you know.

  • How about installing OS on to a USB Flashdisk. Is it possible? If so, how can we do it? Thanks :)

    I have tried install XP but always get BSOD on startup.

  • I tried Diskmod.sys with Win 7 SP1. It does not work to disguise USB Flash Drives as USB HDDs

  • Please make a note that these options DO NOT WORK with 64bit Windows 7. The first two simply do not work, the third rendered my system unbootable.

    • Behaviour confirmed! on Win 7 64bit all these filters doesn’t work

      • Is there an alternative for us Win 7 64bit users? I have my flash drive partitioned just fine but need to use the other partitions without using Bootice.

        • Latest version of RMPrepUSB has a feature to set any one of four primary partitions as the accessible one in Windows (similar to Bootice function)

  • You can install Diskmod on Windows 64 bit by enabling TESTSIGNING.
    Execute the following command and then install Diskmod on 64 bit Windows.
    Bcdedit.exe -set TESTSIGNING ON

    I have updated the article with this command

  • Trying to run this on win 8 but it tells the driver is not digitally signed?
    Any advice?

  • Karyonix – diskmod.sys

  • I could not make my Toshiba PC with integrated SD reader, to recognize it as HD… but, if I plug an USB Flash, then it recognize it as a HDD (DiskMod.sys)

    I will try to tweak the registrery about the enum SD branch…I think that the values there are the key of this…

  • 1) Download and extract diskmod-0.0.2.2.zip

    2) Right Click on diskmod.inf – Install

    3) Run UFDasHDD.bat and replug your USB Flash Drive to make it appear as Fixed Disk

    I got a question regarding about step 3.

    I copy the diskmod-0.0.2.2.zip into the USB 3.0 pen drive, using PC 1.

    I took the USB 3.0 pen drive, and stick into the USB 2.0 port of PC 2.

    PC 2 boots up and took a long time to load all drivers.

    I finally got into Window 7 x64, and it is in TEST MODE now.

    I unzip the diskmod zip file, and install diskmod.inf, reboot my PC 2.

    I went back to the folder- diskmod, and run as Admin on the UFDasHDD.bat.
    I can only see a few seconds, of the command prompt did some thing and closed.

    Now this step puzzle me, replug the drive, meaning physically pull out the
    pen drive and plug it back again?

    Thanks

    • Yes. You need to physically pull out the pen drive and plug it back again.

  • How to uninstall diskmod ?

  • I tried diskmod, and it was disaster ! Still have no USB access – instead having multiple partitions accessible I can not access SD cards at all. And for some time I lost most of my partitions on hard disks too. Indeed worst piece of SW I tried in last 10 years. Avoid like plague ! And where is unisntall option ? Now I need to spend another 2 hours while figure out how to complete remove this crap …

  • After little googling found uninstall script, which even works, it seems :

    http://reboot.pro/topic/9461-page-file-in-usb-hard-disk/page-2

    Now, I really don’t want to be negative or harsh, but according to comments here and on some other forums, diskmod has serious problems on many configurations. For me it seems more as some hack, what worked for author, but is really not recommended – because high risk of making system useless, damaged, or at least just because multiple partitions on removable will work not.

  • OMG I can’t uninstall diskmod, because reboot.pro is down and I can’t download the diskmod_uninstall.inf! Could someone please print it out here? diskmod didn’t work on my win7 64bit and now I can’t see my usb.

    • [Version]
      Signature=”$WINDOWS NT$”
      Provider=%Provider%
      DriverVer=12/12/2009,0.0.2.2

      [DefaultInstall.ntx86]
      DelReg=DelReg_DiskModClassFilter
      DelFiles=DelFiles_DiskMod_x86

      [DefaultInstall.ntamd64]
      DelReg=DelReg_DiskModClassFilter
      DelFiles=DelFiles_DiskMod_amd64

      [DelReg_DiskModClassFilter]
      HKLM,SYSTEM\CurrentControlSet\Control\Class\{4D36E967-E325-11CE-BFC1-08002BE10318},LowerFilters,0×00018002,diskmod

      [DefaultInstall.ntx86.Services]
      DelService = diskmod

      [DefaultInstall.ntamd64.Services]
      DelService = diskmod

      [DelFiles_DiskMod_x86]
      diskmod.sys

      [DelFiles_DiskMod_amd64]
      diskmod.sys
      diskmo64.sys

      [DestinationDirs]
      DefaultDestDir=12

      [SourceDisksNames]
      1=%DiskName1%,,,”"

      [Strings]
      Provider = “Karyonix”
      DiskModService = “DiskMod Filter Driver”
      DiskName1 = “DiskMod Installation Disk”

    • BTW: it worked for me… with an cardbus memory-reader… so, I moved the paging file to it… XP sp3

  • It is now on. But I will paste uninstall script here, for case :

    diskmod_uninstall.inf :

    [Version]
    Signature=”$WINDOWS NT$”
    Provider=%Provider%
    DriverVer=12/12/2009,0.0.2.2

    [DefaultInstall.ntx86]
    DelReg=DelReg_DiskModClassFilter
    DelFiles=DelFiles_DiskMod_x86

    [DefaultInstall.ntamd64]
    DelReg=DelReg_DiskModClassFilter
    DelFiles=DelFiles_DiskMod_amd64

    [DelReg_DiskModClassFilter]
    HKLM,SYSTEM\CurrentControlSet\Control\Class\{4D36E967-E325-11CE-BFC1-08002BE10318},LowerFilters,0×00018002,diskmod

    [DefaultInstall.ntx86.Services]
    DelService = diskmod

    [DefaultInstall.ntamd64.Services]
    DelService = diskmod

    [DelFiles_DiskMod_x86]
    diskmod.sys

    [DelFiles_DiskMod_amd64]
    diskmod.sys
    diskmo64.sys

    [DestinationDirs]
    DefaultDestDir=12

    [SourceDisksNames]
    1=%DiskName1%,,,”"

    [Strings]
    Provider = “Karyonix”
    DiskModService = “DiskMod Filter Driver”
    DiskName1 = “DiskMod Installation Disk”

  • Thanks for the help. I am really struggling for the solution. One question , will it work on any USB drive brand?

  • Yes, it should work on any one.

  • Can you reupload it files to mediafire please? In dropbox always get error 509 :(

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