Installing 3.4 to USB flash drive

[gold_finger]

Unless the "live" USB was made with a persistence file the changes made will only last during the current boot session.  Every reboot will start fresh again and nothing you changed/saved/installed during the last session will be there.  Sounds like you just have a normal "live" USB without persistence, which is why nothing gets saved.


You have two options:

1. Use UNetBootin to make the USB and tell the program to create a 4GB persistence file.  That's easy to do and you'll see the line(s) asking about that during the install to USB.  Just tick the box saying you want to use persistence and fill in 4096MB for the size of it, (which is the max. size it will allow).  Note:  this will result in most of the 16GB USB stick being unused -- it will use only the size of the ISO file plus the 4GB persistence file.  Also, running system updates on a live USB may not always work well -- at least that's been my experience, but I haven't tried doing that in years so I could be wrong on this.
   
2. Do as Daveyboy suggested and perform a full installation to the USB stick (like you would to a hard drive) instead of making a "live" USB.  I lean in favor of this myself, especially if you plan to run updates frequently and if you're planning to use the USB primarily on one computer.  To do a full install you'll need a live USB/DVD to install with and a 16GB or larger USB stick to install to.  Boot the live USB/DVD, plug in the USB you plan to install to, then use GParted to create install partitions on it.  For the 16GB USB, I'd make one 15GB ext4 partition and one 1GB Swap partition.  Once that's done, close GParted and start the installer.  Direct installer to use the 15GB partition you made and set it as the root partition with the mount point noted as "/".  Also, make sure to tell the installer to put the Grub boot loader on that USB stick as well, otherwise it will automatically put it on the hard drive of the computer you're using during installation.  (You don't want that to happen!)
   

If you decide to do the full install vs. live with persistence and are not sure about any of instructions above, post back and ask for more details.