For example, you may have a BIOS.BIN and FLASHBIOS.BAT file you need to run in DOS. To actually run these files from DOS, you will need to copy them over to your newly-formatted USB drive. You have probably created this boot drive because you have a DOS-based program to run, such as a BIOS update utility or another low-level system program. The formatting process should be extremely quick-usually a matter of seconds-but it can take longer depending on the size of your USB drive. Select the “Create a bootable disk using” option and then choose “FreeDOS” from the dropdown menu next to that option.Ĭlick the “Start” button to format the disk and copy the files necessary to boot into FreeDOS. The DOS option requires FAT32 and isn’t available for the other file system options like NTFS, UDF, and exFAT. RELATED: What's the Difference Between FAT32, exFAT, and NTFS?įrom the “File System” dropdown menu, choose the “FAT32” format. Note that this process will erase the contents of your USB drive, so make sure you’ve backed up any important files on the USB drive first. First, connect your USB drive to the computer and select it in the “Device” dropdown menu. Creating a DOS-bootable USB drive in Rufus is simple.