I use a lot of external USB drives (about 7 different drives) for storage an backups. When you set up a backup or synchronization job in most programs you have a problem when using USB drives: without a fixed drive letter always assigned to the same drive you won’t be able to use backup or synchronization templates. Most programs that references files on an external medium doesn’t really like when the drive letter changes each time you plug it in.

The solution is a small freeware program called USB drive letter manager, or short USBDLM, that can be found here (download link is at the bottom of the page).

After extracting the contents of the downloaded zip file to a folder you have to edit a config file to provide the program with the necessary information. Here’s a short tutorial on how to get it running.

1 – Installation

Extract the contents of the downloaded zip file into a folder of your choice. Run _install.cmd to initialize the program, from now on it will always be running.

2 – Configuration

Now you need to gather information on your USB drives to identify them and tell which letter to be assigned to which drive. Connect your USB drives to the computer and run the file ListUsbDrives_To_Notepad.cmd. This opens up a text editor window containing all necessary information. Since all my drives are of a different built, I use the parameter Friendly Name for identifying the drives, if you have several drives of the same built use the parameters Drive DevID or Ctrl DevID.

Let’s say my drives Friendly Name is SAMSUNG HD103UJ and I want the letter F:\ assigned to it.

Just open the config file USBDLM.ini and place code like this snippet in there

;1000 GB Samsung HDD in black Icy Box
[DriveLetters10]
DeviceID1=SAMSUNG HD103UJ
Letter1=F

The first line is just a comment. The number in the second line behind “DriveLetters” is supposed to be incremented with every drive you add (10, 20, 30, …) but while writing this blog entry I noticed that I actually failed to do so when I set up my file a few months ago and it worked anyway. In the third line you insert the value of Friendly Name, Drive DevID or Ctrl DevID to tell the program which drive to assign a letter to. And in the last line you specify which drive letter it should be. That’s all.

Next time you plug in that drive it is automatically assigned the letter F:\ even if D and E are still available. Voilà, fixed drive letters for external USB drives.

3 – Summary

It takes about 5 minutes to configure this neat little freeware program for several USB drives, but once that is done you don’t have to touch it again unless you get a new drive. The program can actually do much more than just assigning letters by the drive name criterion, the included help file which is also available here elaborates quite extensively on any possible way of configuring it.