If you need to make copies of a bootable drive, just copying the files is not enough. You’ll need to create an image. Passmark’s ImageUSB is a third party tool perfect for this job as it is easy to use and does not need to be installed. Once you create the image you can use ImageUSB to copy it to other USB drives.
1) Open https://www.osforensics.com/tools/write-usb-images.html in any browser.
2) Click the Download button to download the tool.
3) Click on the downloaded file to unzip the file.
4) Click imageUSB.exe to launch the tool.
5) Select the USB drive for you are creating an image.
6) Under Step 2, select Create image from USB drive.
7) Click Browse to select a location to store the image.
8) Type a filename in the Save as dialogue box.
9) Click Save to assign the location.
10) Under Step 4, click Create.