Letters by Device Type



Letters by Device Type


The device type is something USBDLM specific to give some special devices a special handling.


Defined types are:


  • MSCR                 -> Multislot-Cardreader (is always a CardReader too)
  • CardReader           -> drives with characteristic strings like 'Card' or 'Reader' in the device name
  • U3                   -> U3 flash drive or a harddisk with virtual CD-ROM drive e.g. for installing encryption software
  • Floppy               -> Floppy drive
  • VirtualDrive         -> all virtual drives as Subst, Network, TrueCrypt and other drives which are not full blown volumes
  • SubstDrive           -> Subst drive
  • DokanDrive           -> Virtual drive created by Hiroki Asakawa's user-mode file system library
  • TrueCrypt            -> a drive that is used as TrueCrypt container (or as container for any other encryption software, e.g. FreeOTFE), in fact volumes with random data in the first sector
  • ReadSharingViolation -> read access to the volume caused ERROR_SHARING_VIOLATION, usually an already mounted TrueCrypt container
  • TrueCryptVolume      -> a mounted TrueCrypt volume (only supported for [OnArrival]/[OnRemoval] events, not for drive letters!)
  • VeraCryptVolume      -> a mounted VeraCrypt volume (only supported for [OnArrival]/[OnRemoval] events, not for drive letters!)
  • OtfeVolume           -> a mounted OTFE volume (only supported for [OnArrival]/[OnRemoval] events, not for drive letters!)
  • BitLocker            -> a BitLocker volume
  • AllZero              -> first sector contains zeros only (unformatted or non Windows drives)
  • ReadError            -> Read data from the drive failed
  • UnrecognizedVolume   -> Windows says ERROR_UNRECOGNIZED_VOLUME, e.g. Ext3 volume or exFAT on XP without KB955704 installed
  • WindowsRecovery      -> Windows Recovery partition (partition type 0x27 or PARTITION_MSFT_RECOVERY_GUID on GPT)


VirtualDrive, SubstDrive, DokanDrive, TrueCryptVolume, VeraCryptVolume and OtfeVolume are relevant for virtual drives only, so they make no sense in  DriveLetter sections.


The UsbDriveInfo tool shows the types.



Sample for multislot cardreader at L, M, N, O






Sample for multislot cardreader in an NTFS folder using the device name:






It creates there one subfolder for each slot using the device name of the slot. Better card readers have 'talking' drive names like 'USB2.0 CF_MD', 'USB2.0 SD_MMC' and so on. Slots of no name readers have all the same, non talking name like 'USB USB', 'Generic USB', 'General Flash Disk'...

USBDLM removes the folders when the card reader is disconnected.



A multislot cardreader is seen as such if it has three or more independent slots. Furthermore devices with two slots and 'reader' or 'card' and 'flash' in the device name.

Non-USB reader often seen in notebooks are not seen as MSCR. Configure it using the device ID then.


Sample for a SD reader in a laptop with BusType SCSI:







The BusType can be omitted here since V4.3 because a DeviceID is defined which is definite enough.



Sample to remove the drive letter of drives that are used as TrueCrypt container:







Sample to hide U3 AutoRun CD-ROMs:








U3 is a standard fur USB drives which allows to have all programs, data and settings on this drive and work with it on any computer without leaving any traces there.

For that there is the "U3 launchpad" on the drive which shall start automatically when the drive is attached. But Windows executes the open= line in the an autorun.inf on CD drives only. Therefore these U3 drives contain a fake CD-ROM drive with the autorun part. This is the "U3 autorun drive" mentioned above.


If you don't need this, then you can configure an NTFS folder for it. Then you get rid of its autorun and you save a drive letter. Or just configure nothing in this section and remove the drive letter in the Windows disk management.


To remove the U3 functionality completely and irreversibly then use the U3 uninstall tool:



USBDLM sees all USB devices as U3 which have a CDROM and a data drive. This can be the case too on drives with encryption software or on promotion thumb drives.


Meanwhile you find such nasty CD-ROM drives on WLAN sticks and printers too for selfinstalling

drivers... USBDLM does not recognize such drives as fake CD-ROMs so far.