The DeviceType registry entry value is truncated when the Microsoft Storport driver is installed on a computer that is running Windows Server 2008 or Windows Vista
The Microsoft Storport driver (Storport.sys) is installed on a computer that is running Windows Server 2008 or Windows Vista. Then, you notice that the value of the DeviceType registry entry for storage devices is truncated to half of its length.
Note The DeviceType registry entry is located under the following registry subkey:
HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\Scsi\Scsi Port [x]\Scsi Bus [x]\Target Id [x]\Logical Unit Id [x]
In this subkey, [x] is a placeholder for a one-digit number.
For example, the value of the DeviceType registry entry may be truncated to “MediumChang” when the registry entry that is expected is “MediumChangerPeripheral.”
Therefore, applications may function incorrectly when they retrieve the device type information from the DeviceType registry entry.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB953390.