After making sure to select the correct items above, press the Install button (3).Click Refresh in Part List to select Whole disk (MBR) (2).Click Refresh in the Disk section to select the correct USB (1).On the software Grub4dos, you set the following parameters: GUI of Grub4dos - The purpose of running using this software is to make your USB BOOT possible Step 2: Run the Grub4dos software that you just downloaded. Remember to carefully format the USB in FAT32 standard!