Users can format a USB in several different ways. They can format it under Windows or switch to Linux. Those wanting to format it under Windows will need to open the control panel, then under administrative tools, select disk management. After right clicking, the user needs to select the format on the USB flash drive. Users can also do this by putting the key in the USB port. It is also possible to format using Linux. In this case, users should be able to create partitions without too many problems.
To format a USB flash drive to FAT in Mac OS, do the following:
Open Disk Utility,
Select the icon of the USB key on the left side of the window.
Click the Partition tab in the right part of the window.
Replace Current with 1 partition.
Click on Options.
Choose Master Boot Record (MBR).
Click OK to confirm the selection. Then back in the main window, choose the MS-DOS (FAT).
Give a title to this volume and the bottom of the window, click Apply.