If you have bootable USB thumbdrive with some useful content, and want to temporarily reuse it for other purpose, then you can save its contents to image file, and restore it later.
1) Run FlashBoot Free or FlashBoot Pro, click Next
2) Choose "USB imaging and duplication" in the the Main Menu
3) Choose "Save USB storage device to image file" in this menu and click Next
4) Specify source USB storage device and click Next
5) Specify target image file click Next
6) Check summary information and click Save Now
7) Wait for process completion
8) Image file is ready for use. Click OK to exit
