I have installed Kali Linux onto a Live USB using
dd if=kali.iso of=/dev/sdb1
However, upon boot it just has a flashing _ in the top left corner...
I'm assuming you're on a UNIX system, because you can use dd, so, if you are on Linux, the command should be:
dd if=kali.iso of=/dev/sdb1 bs=512k
For Mac:
dd if=kali.iso of=/dev/sdb1 bs=1m
You may have a corrupted flash drive from the block size not being right. Another note, you have to make sure that your flash drive is BIOS and not an EFI boot. If you have BIOS, make a BIOS bootable. if your flash drive is EFI make sure your system is.
dd if=kali.iso of=/dev/sdb bs=512k
2. you sure you used the correct 32/64bit iso? 3. Is your BIOS set to boot from USB?