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Several Ways to Get the Missing Drive Letters Back in Windows

  • Contents:


    A Brief Introduction to Drive Letter


    A drive letter is a single alphabetic character A through Z that can be assigned to physical disk partition, floppy disk drive, removable device, CD-ROM, or even a mapping network drive in the computer. Generally, drive letter A: is allocated to the first floppy disk drive , B: to the second floppy disk drive, and C: to the first disk partition where the running Windows is installed. And the remaining drive letters can be assigned to other disk partitions, removable devices and mapping network drives in accordance with actual demands.

    Once a letter is allocated to a disk partition or mapping network drive (letter for removable devices is changeable), we can say it is fixed unless we change or remove it in Disk Management, Diskpart, or some third party programs.

    However, one day we may find these fixed drive letters are missing in either Windows Explorer or Disk Management, which brings much inconvenience or even makes the partition inaccessible.

    Therefore, we wrote this post and introduce 5 different situations where drive letter disappears, and at the same time show ways to get the missing letter back.

    Drive Letter Missing from Windows Explorer or My Computer


    Generally, after we open the Windows Explorer, we can see the following scenario:

    there is drive letter in windows explorer 1

    Every local drive and every removable storage device has its own letter, like C: for the first drive, A: for floppy drive, and E for DVD drive. But one day we suddenly found all drive letters disappear, which is so strange though this brings nearly no influence on system running and data access:

    drive letter missing from windows explorer 2

    What’s wrong? Where are these drive letters going? How can we get these lost drive letters back in several steps? Let’s deal with these questions one by one.

    The most probable reason may be that you or someone hide drive letters via making settings in Windows Folder Options. To fix this issue, please take the following steps: go to one of partitions, click "Organize" tab, and choose "Folder and search options" from the drop-down menu to get the Folder Options (take Windows 7 for example):

    show drive letter in folder options 3

    Then, select the "View" tab and scroll down the sliding handle to the middle until the "Show drive letters" appears. With checking this option and click "OK", we can see the missing drive letters in Windows Explorer again.

    If you have known the reason for missing drive letter from Windows Explorer or My Computer as well as the solution, it’s time to know why drive letter disappeared from Disk Management.

    Drive Letter Disappears in Disk Management


    As we know, Disk Management is a Windows snap-in partitioning program designed to help Windows users manage disk and partitions. In Disk Management, every drive should have a drive letter, but sometimes we may find one or some of drives lose their letters like this:

    drive letter missing from disk management 4

    Here we can see the 188.38GB NTFS partition does not have a drive letter. Generally, if a partition is not allocated with a letter in Disk Management, it will be invisible in Windows Explorer:

    partition without drive letter in disk management is invisible in windows explorer 5

    As a result, we are unable to directly access files saved in it, and all programs relying on the drive letter will be unavailable. Therefore, under this situation users would be more eager to get the missing drive letter back.

    Then, let’s see how.

    Steps to Get Missing Drive Letter Back in Disk Management


    In Windows Disk Management, the function "Change Drive Letter and Paths", which appears in the right-click menu of a partition (Windows calls it volume), can help add, change, and remove drive letter:

    add change and move drive letter in disk management 6

    If "Remove" is selected and applied, the letter of the target drive will be removed and disappear in Disk Management, which is one of reasons for losing drive letter. On the contrary, by clicking "Add", we can assign a letter for the selected drive. Therefore, when certain drive loses its letter, we can try adding a drive letter in this way. But for successful adding, you may need to pay some attention to the following tip:

    Tip: You’d better assign the drive with the original letter. If not, programs relying on the original letter might not work correctly. If the original letter has been taken by new drive, change the letter of the new drive to another available letter and then allocate the released one for the target drive.


    In addition, partitions hidden via special technologies (set partition type ID to 0x17, for example) are always having no letter. If a partition is hidden, the function "Change Drive Letter and Paths" for this partition in Disk Management will be unavailable (grayed out). At this time, the best solution is to unhide the partition by using third party program. If you failed to assign a letter for your drive in Disk Management, now try using MiniTool Partition Wizard Free edition to unhide partition, which is a freeware for Windows home users.



    Partition Wizard Makes It So Easy to Unhide Partitions

    Step 1. Run and launch the freeware to get its main interface:

    unhide partition in partition wizard select the hidden partition 7

    Step 2. Select the hidden partition and click "Unhide Partition" from the left action panel.

    unhide partition in partition wizard assign new drive letter 8

    Step 3. Select a letter for the partition and click "OK".

    Step 4. Click "Apply" button on the top to apply the change if the missing drive appears in Partition Wizard.

    When MiniTool Partition Wizard shows it succeeded in applying the operation, letter of the partition will be visible in Disk Management, and the missing drive will also appear in Windows Explorer.

    After getting a basic understanding of the second scenario, next let’s see the third one.

    Drive Letter Missing from the List of Available Drive Letters


    We have said it is very easy to add or change drive letter for certain partition in Disk Management, but sometimes you may find such a strange situation where a specific letter is not shown in the list of available drive letters and no other device has that letter assigned. The most probable reason may be that this letter is reserved for a removable device that was removed or is hidden.

    Under this situation, if you want to assign the very letter for the specific drive, you may need to make some modifications in Registry. However, as a slight mistake in Registry may cause data loss or system crash, it is very necessary to backup the registry before doing any modification. For detailed steps, please see How to Backup and Restore the Registry in Windows.

    Then, launch Regedit, navigate to HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices, and see if a device is shown as being mounted at the specific drive letter. Next, right click the drive letter that you want and choose "Rename" from the right-click menu to change the letter to any other unused letter, which will free up the selected one.

    rename drive letter in registry 9

    After reboot, you can add the released letter for your drive. And next, let’s see the fourth reason for losing drive letters.

    Drive Letter Disappears after Reboot


    When browsing Windows Forum and Windows Seven Forums (2 well known technical forums about Windows) I found a lot of people were talking about the problem that drive letters disappear after every reboot. Of course, the same issue can be found in other websites or forums since this is a quite common error. Next, let’s see an example coming from Windows Seven Forums.

    The following screenshot shows the 465GB NTFS partition on Disk 1 has the letter E:

    before drive letter is missing

    However, after every reboot, the letter will be missing:

    drive letter is missing after reboot 11

    If the user wants o use the partition normally, he has to assign drive letter every time, which is so troublesome.

    After lots of searches on Google I found this error often occurs on Western Digital hard disk, so it may be a bug of WD hard disk. And someone gives the suggestion: fill the disk with zero MiniTool Partition Wizard, which is a freeware for Windows home users, can help complete this task in very simple steps.

    However, before zero filling the hard disk, users need to backup all desired files, because this will erase both file system and data. For steps to backup a disk, please see Copy Disk. After the backup has been created, we can wipe the disk without any worry.

    How to Erase Disk with MiniTool Partition Wizard




    Firstly, run and launch the freeware to get its main window below:

    erase disk in partition wizard select target disk 12

    Here we can see all recognized hard disks. To wipe a disk, please select the target disk and click "Wipe Disk" feature from the left action pane to get the following interface:

    erase disk in partition wizard select wiping method

    There are 5 wiping methods in total, including Fill Sectors with Zero, Fill Sectors with One, Fill Sectors with Zero & One, DoD 5220.22-M (3 passes), and DoD 5220.28-STD (7 passes), and you can choose one of them to erase the hard disk. From the top to the bottom, erasing time increases but the effect is better and better. Then, click "OK" to go back to the main interface:

    erase disk in partition wizard apply changes 14

    From the above interface we can see the entire hard disk 2 becomes unallocated, and there are 3 pending operations on the left side, containing delete partition I, delete partition H, and wipe disk 2. At this time, as long as we click "Apply" button, all changes will be made automatically. Once the disk is erased, we can recreate partitions in either Disk Management or Partition Wizard. And the new drive letters would stay in their original place next time you reboot the computer.

    Now if you have known how to deal with the issue that drive letter is missing after Windows reboot, let’s see the last situation.

    Drive Letter Missing in Map Network Drive


    Drive mapping is how operating systems like Windows associate a local drive letter (A through Z) with a shared storage area to another computer over a network. However, these local drive letters may disappear in Windows Explorer without us knowing exact reasons. After a series of findings, we find 2 possibilities:
    1.When mapping the drive, users do not check the option "Reconnect at logon".
    2. Use the Work online without synchronizing changes over a virtual private network (VPN) connection.

    Now that reasons are found, solutions are available now. For the first situation, users just need to remap the network drive and check "Reconnect at logon":

    reconnect at login

    For the second situation, please obtain the latest service pack for Windows, or apply Hotfix to the system that is experiencing the problem. For more details, please see Drive Letters of Mapped Network Drives Are Missing in Windows Explorer of Microsoft.

    Is your drive letter missing or lost under Windows? Have your found the exact reason and corresponding solutions? If you have found, can you please share them with us if they are different from those introduced in this post? If you haven’t found goo solutions, this post may be useful.