How do you make a Hiren's bootable USB flash drive in Ubuntu

Quickest way is to install UNetbootin and create a USB drive from there. You can create any bootable Live USB drives, such as Linux and windows, without requiring you to burn a CD.
1) Go to Ubuntu Software Center
2) Search for UNetbootin, then click Install
3) Once installed, open UNetbootin from your Ubuntu machine
4) Check Diskimage ISO and then your Hiren's ISO (or any ISO you want make bootable on USB) file from your harddrive
5) Select you USB Drive, then click OK. Once it's done, you have a bootable USB drive with Hiren's.