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
- USB Flash Drives cannot be partitioned using Windows Disk Management
- USB Hard Disks can be partitioned using Windows Disk Management
- Third Party Tools can partition a USB Flash Drive. But all partitions will not be visible.Only the first partition will be visible
- 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
Hitachi Microdrive Filter Driver – cfadisk.sys
Video Tutorial for installing Hitachi Microdrive Filter Driver
Install Hitachi Microdrive Filter Driver
- Download cfadisk.zip.I have modified the cfadisk.inf to work with all USB Flash Drives using USBSTOR\GenDisk as posted by cdob@msfn
- Open Device manager (devmgmt.msc) and check for your USB drive in “Disk Drives”.
- Right click on the entry for your drive and select option to update driver.
- Don’t use windows update
- Browse my Computer for driver software – Locate and install driver software manually
- Let me pick from a list of device drivers on my computer
- Have disk
- Browse to location of downloaded cfadisk.inf
- 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
- Download dummydisk.zip and extract the package
- Run INSTALL_DUMMY.cmd
- Reboot the computer
Run REMOVE_DUMMY.cmd and reboot
- 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
- Download and extract diskmod-0.0.2.2.zip
- Right Click on diskmod.inf – Install
- Run UFDasHDD.bat and replug your USB Flash Drive to make it appear as Fixed Disk
- Run UFDNormal.bat and replug your USB Flash Drive to make it appear normally as Removable Media
- Run USBHDDasUFD.bat and replug your USB Hard Disk to make it appear as Removable Media
- Run USBHDDnormal.bat and replug your USB Hard Disk to make it appear normally as Fixed Disk.
- 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.