Is it previously booted?
wipefs --all /dev/sd[letter]
Is it currently for file storage? OK.*
mkfs.vfat -n 'PENDRIVE NAME' -I /dev/sd[letter]
Setting the actual .ISO**
dd bs=4M if=path/to/ISO of=/dev/sd[letter] status=progress oflag=sync
Check your partition tables in order to see if it is isohybrid (you can do it before all this process with the .ISO tho.)
fdisk -l /dev/sd[letter]
- PS1: * 'PENDRIVE NAME' doesn't need the single quotation marks.
- PS2: ** Careful with your disk. Be sure to select the USB device or you will wipe your HD.