Windows Doesn’t Assign Drive Letter to External and USB Flash Drives

Faced with such a problem: when I connect any external removable USB HDD or flash drive, Windows doesn’t assign a drive letter to it. When a drive is connected, a message appears indicating that a new device is installed, the drive appears in the Device Manager, but is not displayed in the File Explorer.

To make the drive available in the system, you must assign a drive letter through the Disk Management console each time manually. To do this, open the Computer Management console (via the Win + X menu) and go to the Storage section -> Disk management. In the list of drives, locate the connected removable USB drive. As you can see, the disk is online, it has one healthy partition with the NTFS, but it is not assigned with a drive letter. To assign a drive letter to it, right-click on the partition and select “Change Drive Letter and Path“.

In the window that appears, click the “Add” button, select “Assign the following drive letter” and select the letter you want to assign to the drive (for example, H: ) in the drop-down list and click OK.

After that, the connected USB drive appears in the File Explorer with the assigned drive letter. However, after disconnecting the USB device or restarting the computer, the drive letter won’t be assigned automatically to it. I have to assign the letter again manually through Disk Management, and that becomes annoying.

It seems that some feature of automatic detection of partitions on the external hard disks fails. How to solve this problem?

First of all, make sure that the Virtual Disk service is running. You can check the status of this service in the services management console (services.msc).

Or from the command prompt:

sc query vds

SERVICE_NAME: vds
TYPE               : 10  WIN32_OWN_PROCESS
STATE              : 1  STOPPED
WIN32_EXIT_CODE    : 0  (0x0)
SERVICE_EXIT_CODE  : 0  (0x0)
CHECKPOINT         : 0x0
WAIT_HINT          : 0x0

If the service is stopped, start it from the graphical snap-in (Start button) or using the command:

net start vds

Check if the problem persists. If it does, make sure that the automatic mounting of new volumes is enabled.

Open the command prompt as administrator and run the following commands:

diskpart

Within diskpart, make sure that the automatic mounting of new volumes is enabled:

DISKPART> automount

Automatic mounting of new volumes disabled.
As you can see, the auto-mounting is disabled. Let’s enable it:

DISKPART> automount enable

Automatic mounting of new volumes enabled.
Exit diskpart

DISKPART> exit

Leaving DiskPart...

Restart your computer and verify if the letters are assigned to the external USB drives.

If not, check if the “hidden” and “do not assign a drive letter” attributes are set for the partition on the USB drive. Run the Diskpart command line and enter the following commands:

1. List the disks: list disk
2. Find the disk number assigned to your USB flash drive (in this example 1) and select it: select disk 1
3. List the partitions on the disk: list part
4. Select the desired partition: select partition 2
5. Check the partition attributes: attributes volume
6. As you can see, the “Hidden” and “No Default Drive Letter” attributes are enabled for this volume;
7. Disable these attributes with commands:
   attributes volume clear NoDefaultDriveLetter
attributes volume clear hidden
   Volume attributes cleared successfully
8. End the diskpart session by typing: exit

After that, this partition on the USB flash drive should automatically be assigned a drive letter on any computer.

Also keep in mind that if there are several partitions on the USB flash drive, then Windows will only see the first partition. The ability to create multiple partitions on removable USB drives appeared only in Windows 10 1703. Previously, in order to make second and subsequent partitions on the USB flash drive were accessible in Windows, you had to use a trick to make Windows recognize USB flash drive as a HDD). If your USB flash drive doesn’t appear in the Disk Management console, try using a different USB port, cable. Try to connect the USB flash drive directly to the computer (without the USB hub), check whether the power is on, and whether it is recognized on other computers.