Abstract: A method of setting hot key includes: triggering an RBSU setting procedure in a system code interface of a BIOS of the computing apparatus, executing the RBSU setting procedure to enter an RBSU setting interface, registering a captured hot key in the RBSU setting interface and establishing a screen image procedure code with respect to the captured hot key. A method of capturing a screen image for applying the foregoing method in a RBSU executing interface includes: triggering an RBSU executing procedure under the system code interface, executing the RBSU executing procedure to enter the RBSU executing interface, determining if the captured hot key is triggered in the RBSU executing interface, executing the screen image procedure code to capture a screen image of the RBSU executing interface if positive, and storing the screen image into a storage apparatus electrically coupled with the computing apparatus.