My 8gb Sandisk cruzer has an image of Kali Linux on it which I am trying to use to boot from.

However, when I go into my boot options, I cant choose to boot from USB even when its plugged in I tried to open it to see what the files were, but I cant go in unti l format it.

When I try to format it, it says it will only have 2.7gbs of space Help would be much appreciated.

Reading a USB drive on a UEFI system simply requires it be in a format Windows recognizes; ie FAT, exFAT or NTFS.

Obviously your flash drive doesnt have one of those formats, and since you say it has a Linux system on it it is probably formatted in a Linux ext format.

If you want the files on it you need to find a non-UEFI machine, boot the Linux system and copy all the files to the machines hard drive, reformat the flash drive to a format Windows supports, then copy the files from the hard drive back to the flash drive.

Another option, after you backup your files, is to put Porteus on the flash drive, it supports booting on UEFI systems.

The solution is to go into the firmware set up and select Legacy Boot which then give you the option to boot from USB.

But to reboot to the hard drives OS you have to change the BIOS back.

I believe I addressed those issues as the only way is to tweek the BIOS to boot the existing device as currently formatted.

Efi Usb Device For Mac