Generally, press f 12 to set the USB flash drive to start, and some models need to press Delete. Here is a detailed explanation of the method of USB flash drive startup:

1, turn on the computer, select Delete, and enter the BIOS settings, as shown in the following figure:

2. In the BOOT Options bar, select Boot Device Priority, as shown in the following figure:

3. Press Enter in 1st boot device, and select your USB flash drive to complete the setup and startup of the USB flash drive. As shown in the figure below: