Drive letter missing!
When you divided your hard disk into several partitions, you’ll give it a letter from
A to Z. That is drive letter. It can be used to physical disk partition, floppy disk
drive, removable device, CD-ROM, or network drive. Each storage drive should be assigned a drive letter. Once the
drive letter missing, you cannot access the drive to get any information.
There are many situations of drive letter missing, and here we have list the top 5
situations:
1. Drive letter missing from Windows Explorer or My Computer
2. Drive letter disappear in Disk Management
3. Drive letter missing from the list of available drive letters
4. Drive letter disappear after reboot
5. Drive letter missing in map network drive
Here is a case of drive letter missing:
“How do I find a missing drive in Windows 7?
For various reasons, I have reinstalled Windows 7 from scratch. When I got to the point where I am telling the installer what I want to do with my hard drives (I have two huge ones) I formatted both hard drives. Now, after I have installed the Operating System, it only recognizes the one hard drive that I put the Operating System on, (the C drive). I guess it does not read from a reformatted drive that it has not written to. How do I fix it so that I can use the second drive?"
Actually, in many cases, drive letter missing is the main reason of hard drive is not showing up. Thus, it is necessary to find drive letter back.
How to get missing drive letter back in Windows 10/8/7?
It is urgent to get the drive letter back when you find it disappeared. For the case we mentioned above, you can do as following steps:
Locate Control Panel > Administrative Tools > Computer Management > Disk Management You will find every hard disk in the list below with names like Disk 0, Disk 1, Disk 2 etc. Find the missing Disk and add a Drive Letter, after this you will see your missing hard drive in My Computer.
Besides the case we mentioned, there are many other situations of drive letter missing. And for different situations, we provide different solutions. You can read on if the method won’t solve your situations.
1. Drive letter missing suddenly in Windows Explorer
If you find the drive letter suddenly missing in Windows Explorer or My Computer, you
need to check whether it is hidden by you or others. If the drive letter is hidden,
here you can do as following steps to get it back (take Windows 10 as an
example):
1>. To configure your Folder Options in Windows 10, you’ll need to begin by
opening up a window in File Explorer.
2>. Then, click on the top left hand File menu, and select Change
folder and search options to get the Folder Options.
3>. Then, select the "View" tab, scroll down the slide
handle to find the Show drive letters option in Advanced
settings and check it, click OK.

After that, we can see the missing drive letters in Windows Explorer again.
2. Drive letter missing because the partition is hidden
If a partition is hidden and you cannot find it and access it, it is a good choice to
turn to a third party software for help. The AOMEI Partition Assistant should be a great partition software that can make things go
easier. If your computer is base on Windows Server 2003, 2008, 2012, 2016, 2019, the AOMEI
Partition Assistant Server Edition can help you settle all partitions
problems.
Install AOMEI Partition Assistant to your computer based on Windows 10/8/7. it will
show you all partitions on your computer no matter it is hidden or not. That means
here you can clearly see whether your partition is hidden.
To unhide the partition, here you can do as follows:
Step 1. Right-click the hidden partition, select Advanced-> Unhide Partition.

Step 2. Click OK to unhide the selected
partition. If the partition has no drive letter after unhiding, please restart your
computer.

Step 3. Click Apply-> Proceed to
execute the task.

After that, the missing drive letter will be back and you can access to the drive
successfully.
3. Drive letter missing in Windows Disk Management
For some situations, you may find that the hard drive is missing in Windows Explorer,
and when you open Disk Management, you’ll find the drive is here but without any
drive letter. Like the screenshot:

For this situation, you are unable to access the drive and get any information stored
on the partition. Fortunately, you can get the drive letter back in Windows Disk
Management:
Right-click the partition/volume whose drive letter missing, select Change
Drive Letter and Paths and click Add... ->OK.

Using this method, you can assign a drive letter for the drive whose drive letter is
missing.
Warning:
It is important to assign the drive with its original drive letter. Otherwise, the
programs relying on the original drive letter might not work correctly. Thus, if the
original drive letter has been taken by a new drive, you need to change the drive
letter of the new hard drive for a new letter to get the drive letter back.
If you find the Change
Drive Letter and Paths grayed out, you can also use the AOMEI Partition
Assistant to assign drive letter to the partition.
4. Get missing drive letter back from Registry
Sometimes, you may find that the letter is not shown in the list of available drive
letters but no drive was assigned with that letter. That may because the letter is
reserved for a removable device that was removed or is hidden. For this situation,
you can get the missing drive letter from Registry. Do as followings:
Tips: It is recommended to backup Registry before doing any
modification in case of data loss or system crash.
1>. Launch Regedit, navigate to HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices.
Check whether there is a device is shown as being mounted at the specific drive
letter.
2>. Then, right-click the drive letter that you want and chooseRename from the list menu, and change the letter to any other used
letter to free up it.

Reboot the computer to assign the released letter to the drive you want.
5. Drive letter missing after reboot PC
Part of users may meet the problem that after reboot their PC, the drive letter
missing. If the drive letter missing after every reboot, you can consider to wipe
the hard drive and recreate partitions. And you can also use AOMEI Partition
Assistant to wipe hard drive or secure erase SSD.
Tips: wipe hard drive or secure erase SSD will delete all data on the disk, thus,
please copy disk or make a backup in advanced.
Here we take wipe hard drive as an example:
Step 1. Right-click the hard drive that needs to be wiped, select Wipe Hard Drive.

Step 2. Here you can choose a wiping method. There are four methods
you can choose, and here we choose Fill sectors with Zero. because besides this way, you need to upgrade to AOMEI Partition Assistant Professional for the other three ways.

Step 3. Finally, click Apply->Proceed to execute the progress.

After the whole progress, you can recreate
partitions on the hard drive with Disk Management or AOMEI Partition
Assistant.
6. Settle drive letter missing in map network drive
Sometimes, you may find the local drive letters may disappear in Windows Explorer
suddenly. That may because of the drive letter missing in map network drive. You may
not check the option “Reconnect at logon”. For this situation, you just need to
remap the network drive and check Reconnect at logon.

Conclusion
There are many reasons would cause drive letter missing. Hope that this article can
help you to solve your problem. If you have any other good methods for settle this
kind of problem, welcome to share it in the comments area.