Posted on October 10, 2014 · Posted in Windows 7

Removable USB Flash Drive as Local Disk in Windows 7

In this article, we’ll show you how to make a USB flash drive or an SD card to be identified in the system as a common local hard disk. You may ask why it is necessary. The matter is that by default Windows identifies all the flash drives and memory cards as removable drives that can not be split into several partitions with any of the standard Windows tools. And even if the USB flash drive is split into two or more partitions using third-party utilities (say, in Linux), only the first partition is available in Windows. I.e. Windows supports working with multiple partitions only for HDDs identified as local (i.e. non-removable) disks in the system.

Information. Windows recognizes a USB flash drives as removable devices due to the presence of a special bit descriptor RMB (removable media bit) on each of the devices. If the system determines that RMB=1 when polling the connected device using StorageDeviceProperty, it concludes that this device is a removable drive. Thus, to make a system see a USB flash drive as a hard disk, it’s enough to modify this descriptor. You can do this directly (which is quite risky because of the differences in the device-specific hardware implementations, and not always possible), or indirectly, by substituting the response of a USB device using a special driver, which allows to filter the information in the response of the device.

Connect the USB flash drive to any available port on the computer, then open the Disk Management console (diskmgmt.msc) and make sure that it is determined by the system as Removable.

removable usb flash drive in windows disk manager console

Also you can view the type of device in the Volumes tab in the properties of the device (as we see here Type: Removable).

removable disk

Or using the command diskpart:

list volume

diskpart check removable drive

Filter Driver for Hitachi Microdrive Flash Drives

To make a USB flash drive or an SD card to be recognized as a hard drive in the system, you need a special filter driver, which allows you to modify data sent via the system stack of the current device driver. We will use a filter driver for USB flash drives by Hitachi (Hitachi Microdrive driver), which allows to change the USB device type from removable to fixed (USB-ZIP -> USB-HDD) at the OS driver level. Using this driver, you can hide from the system that the connected device is removable. As a result, the system assumes that it works with a usual hard disk, which can be split into partitions available in the system simultaneously.

Hitachi Microdrive Driver Files:

You need to download the version of the driver in accordance with the bitness of your system. Both archives have identical structure and consist of two files:

  • cfadisk.inf is the installation file with driver settings
  • cfadisk.sys is a Hitachi driver file

The next step is to identify the device ID of your flash drive. To do it, in the properties of the disk on the Details tab in the Device Instance Path setting, select and copy (Ctrl + C) the code for the device instance.

identify device id

In our example this would be:


Suppose we are going to install a driver on the 64-bit system.  To edit it, open cfadisk.inf in any text editor. We need the sections cfadisk_device and cfadisk_device.NTamd64.

%Microdrive_devdesc% = cfadisk_install,IDE\DiskTS64GCF400______________________________20101008
%Microdrive_devdesc% = cfadisk_install,IDE\DiskTS64GCF400______________________________20101008

Change the value DiskTS64GCF400______________________________20101008 with the ID of your device.

Important! In the code of the device instance, the part after the second “\” should be deleted (we delete 9876543210ABCDEF&0 in our example).

We get:

%Microdrive_devdesc% = cfadisk_install,IDE\USBSTOR\Disk&Ven_Linux&Prod_File-CD_Gadget&Rev_0000
%Microdrive_devdesc% = cfadisk_install,IDE\USBSTOR\Disk&Ven_Linux&Prod_File-CD_Gadget&Rev_0000

Save the file.

If the driver is installed on a 32-bit system, you have to download the corresponding archive, unzip it and open cfadisk.inf for editing. Find the section [cfadisk_device]:

%Microdrive_devdesc% = cfadisk_install,USBSTOR\Disk&Ven_LEXAR&Prod_JD_LIGHTNING_II&Rev_1100
%Microdrive_devdesc% = cfadisk_install,USBSTOR\Disk&Ven_JetFlash&Prod_TS1GJF110&Rev_0.00
%Microdrive_devdesc% = cfadisk_install,USBSTOR\DISK&VEN_&PROD_USB_DISK_2.0&REV_P

Then change the data in the last line, having specified the instance ID of our flash drive, i.e. in our example, we get:

%Microdrive_devdesc% = cfadisk_install,USBSTOR\Disk&Ven_LEXAR&Prod_JD_LIGHTNING_II&Rev_1100
%Microdrive_devdesc% = cfadisk_install,USBSTOR\Disk&Ven_JetFlash&Prod_TS1GJF110&Rev_0.00
%Microdrive_devdesc% = cfadisk_install,USBSTOR\Disk&Ven_Linux&Prod_File-CD_Gadget&Rev_0000


Tip. If you want a USB flash drive in the Device Manager to be displayed under a specific name, you have to edit Microdrive_devdesc variable, e.g., like this:

Microdrive_devdesc = "Trascend 64 GB DIY SSD"

How to Install Hitachi Microdrive Driver Instead of the Native Driver for a USB Flash Drive

You only have to replace the driver used by the USB flash drive.

Important! If Hitachi Microdrive USB driver is installed on a 64-bit system, since this driver is not digitally signed, you will have to disable the verification of the digital signature for this driver or to sign the driver yourself.

Open the Drivers tab and click Update Driver.

update device driver

Specify the path to the directory to which you have extracted the archive with Hitachi driver you had downloaded earlier.

browse path to hitachi microdrive driver

Select the new new driver

Ignore the warning of the missing digital signature of the driver.

ignore driver virify warning

Now you only have to restart the computer and having opened the Disk Manager, verify that the flash drive is identified as a common hard disk (Type: Basic) and uses Hitachi driver.

usb flash drive as basic disk

By opening Windows Explorer, you can also make sure that the icon of the flash drive has changed: it is displayed as a common hard drive.

usb flash as local disk in windows

Now this flash drive can be used as a regular HDD: you can create partitions, specify the active partition, create dynamic disks, install software that does not work from USB flash drives, etc.

Important. Without this driver, the second partition of the device will not be available on other Windows computers.

How to Remove Hitachi Microdrive Driver

To delete Hitachi Microdrive driver, open the properties of the drive and click Update Driver on the Drivers tab. The system will install the native driver.

delete Hitachi Microdrive Driver

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