Ubuntu – Can’t create a bootable ubuntu USB stick with ubuntu

I've used a 1GB flash drive and because of the sheer volume of the ISO image compared to the space on the drive creating some persistent space is not only next to impossible it's also just not feasible because you'd have a VERY small amount of space for stuff to save off to. Grab a 4 to 8 GB flash drive, put on the ISO using the Ubuntu built in USB startup disk maker and it should work. At least it did for me.

One other thing you can also try (I've done it so it should work.) is take an external HD that you can plug into the system via USB (Like a Western Digital backup drive for example.) and then what you do is take out the HD from your pc, plug in the external one into the usb ports, and then you (should be able to) install to that external drive from the ubuntu install menu. Then when you're all said and done you've got an external hard drive that is persistent because well, it's a whole OS!

I would also recommend that you take a look at the following link/question. It goes into a bit more detail on how to do what you're asking... Points down to the link

Install Ubuntu on USB Flash Drive or USB powered external HDD?

You should try unetbootin to make a bootable usb. It's nice and simple

Or from a terminal:

sudo apt-get install unetbootin

also available for windows