USB Duplicator Software for WindowsAdd or update files on USB drives

If you have USB drives preloaded with content, you can use USB Duplicator Now to add new files or overwrite old files on the USB drives.

First, you need to create a new source folder containing just the files you wish to update. Please keep in mind that you need the entire folder structure. If your USB drives have a file called:


and you wish to replace this, you need to create the corresponding source folder structure on your computer. Create your root source folder, for example:


(Feel free create this folder elsewhere as you prefer, just keep that in mind throughout the rest of these instructions). Next, you need to recreate the necessary folder structure, so add a new folder:


Now you can copy your new file into this directory, so the structure looks like this:


Now you're ready to duplicate! Select C:\update-source as the source folder, and all the connected USB drives will be updated with the new file, in the correct location.

But I don't have enough free space...

In some cases, you won't have enough free space on the USB drives for the update. Let's say you have 1000MB drives preloaded with a single 800MB movie. Now you'd like to update this movie to a new 850MB file. So the drives have 200MB space free, and you want to copy in an 850MB file. In this case, the USB Duplicator Now for Windows will tell you that you don't have enough free space for the source files, and will not copy the source files, to avoid corrupting the data on all your USB drives.

Fortunately, there's a workaround for cases like this. Break down the update into 2 tasks:

  1. Copy a small or empty placeholder file over the old file on the drives, effectively clearing space on the drives.
  2. Copy the new file to all the drives. Now that there is enough free space, there is no problem.

So to do this, you need to create a source folder with your empty or small file(*). As in the example given above, you would create:


where in this case is an empty placeholder. Copy C:\placeholder-source to the USB drives with USB Duplicator Now to clear space. Now you can copy the replacement files as normal.


(*) If you need to create an empty file, we have created a service that generates an empty file for you, regardless of the file name or file type. Visit to get an empty version of for use with this workaround. Just copy the URL, and change to the filename you need - it just works!


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