You’ve connected a USB flash drive, heard the familiar Windows sound of connection, yet no drive letter shows up. You then go into Disk Management for Windows and you can see the device and memory, but no drive letter.
What should you do?
Most times this process is automatic and Windows will asign a drive letter to any storage device connected to your PC, whether it be a USB stick or a USB hard drive, or any other mass storage device.
However; in the event a drive letter isn’t assigned there is a very quick way to get your computer back to working the way it should.
- Open Command Prompt as Administrator
(search for CMD and right click to open as Admin)
- Type ‘diskpart’ and hit Enter.
- Once in the DISKPART type automount enable and click Enter.
If the above doesn’t do the trick, another issue may be at hand. Maybe some conflicting registry entries from past USB devices connected to the PC and for this reason the automount was disable, or no longer working properly.
Nexcopy has a registry cleaning tool specifically design for USB devices connected to your computer. This utility is an exe file that does not require installation and does not have spyware, malware or anything else. It’s from a company you may
The link below is for a zip file which has two batch files to either set the USB write protection, or remove the USB write protection for a Windows 10 computer. This batch file also works for Windows 7 machines.
This solution is ultra-easy and very quick. One click to run the reg edit file and one click to confirm the task. That’s it.
Typically a person will want to lock down the USB ports of a computer to insure a virus doesn’t spread to the computer through a USB device, like a flash drive. The nice thing about this batch file is a very quick and easy way to both lock down your USB ports, and equally easy way to unlock your USB ports.
It’s important to note; do not have a USB flash drive connected to the system when you run either batch file.
For those looking for a bit more detail, the information below is the specific registry edit we are making. Changing the dword to 00000001 sets the device policy for the computer to be write protected. Changing that value back to 00000000 will make the USB ports read/write.
It is also important to understand this USB write protect solution is not specific to the USB stick itself. Nor will this solution work on all Windows machines when you move USB drives from computer to computer. Said another way, this change is PC specific.
If you need USB write protection to be permanent to the device and universal to anything the USB is connected to, you may contact Nexcopy.com and ask for their Lock License drives. This is a solution we have found works very well and is done at the controller level of the USB stick itself. Meaning, the USB is write protected for anything it is connected to. The value of this configuration is no chance for a virus to jump onto the USB stick in the first place. This last solution is really the best solution for universal USB write protection.
Here is a screen shot of the two batch files:
The most common reason why only one flash drive is usble when multiple USBs are connected is due to a device signature collision.
If you are dealing with bootable devices and seeing this problem, we are confident a collision is the issue. If you are not dealing with a bootable device, then our information below will, probably, not help.
What is a USB signature collision?
A signature collision can happen on any bootable device, so Compact Flash cards, SD cards, microSD cards and USB flash drives. A disk signature is a unique identifier number (UID). It is a unique identifier stored as part of the MBR (Master Boot Record) for an operating system loaded on the device. The operating system will use the UID to identify and distinguish between storage devices. It is commonly made up of eight alphanumeric characters. A disk collision occurs when your operating system (Windows) detects that there are two disks with identical signatures.
For Windows 7, 8, 8.1 and 10, these versions of Windows will disable the second drive and will not allow that second volume to mount until the disk collision has been rectified. If you are reading this article, chances are, this is exactly what is happening to you.
The first thing to do is navigate to the Disk Management tool with in Windows. To do this, use the search tool and type in Disk Management. This will take you to the utility that Windows offers. Here you can see your multiple devices connected. If you click or hover over the device not working you will see one of two messages:
This is happening on Win8 and Windows 10.
When I remove a USB drive and reconnect it, Windows will not assign a drive letter. Clearly this is a problem as every other computer I use assigns a drive letter.
There are three solutions. All of which will work.
1) You can go into Disk Management and select the device and assing a drive letter. This is a manual process and not ideal for each time you plug in a flash drive.
2) Good chance the driver or registry entry for that device is rogue or corrupt. Use this USBScrub tool to remove the registry entry. Chances are this will fix the problem. USBScrub link
3) Use ‘diskpart’ and enable the automount feature.
- Open Command Prompt as Administrator (search for Command Prompt in the Start Menu, right click, Run as Administrator)
- Type ‘diskpart’ and hit Enter.
- Once in the ‘diskpart’ command prompt type ‘automount enable’ and hit Enter.
- Type ‘exit’ and click Enter
For solution number one from above, Disk Management is really the GUI version for diskpart, but a GUI (Graphical User Interface) which has scaled down functions from what all the things diskpart can really do.
Diskpart has 37 commands that you can do very cool things with. The 38th command is
We have read on-line that Microsoft’s May 2019 update might not happen for those with connected USB sticks or SD cards. Microsoft claims the update will simply not happen if the OS detects these connected devices. The reason, Microsoft might re-assign drive letters to those connected devices.
On my first pass of reading this, the reassignment of drive letters doesn’t sound all that bad. Especially for a removable drive. However; Microsoft goes on to state that internal hard drives could also be affected by the drive letter shuffle.
There is your red flag!
The newly published Windows 10 support document reveals; those computers already having the April 2018 (version 1803) or October 2018 (version 1809) updates installed will receive this error message: “This PC can’t be upgraded to Windows 10.”
The Microsoft documentation does not referrence internal hard drives getting reassigned drive letters when no USB or SD card is detected and for that reason we feel you are safe during the update process. This is why Microsoft is blocking the update all together when a USB or SD card is detected in your system. Microsoft understands the importance of mounted internal hard drives; thus their blocking of the update.