Now edit D:\syslinux.cfg (assuming D:\ is where your USB drive is) and add in "persistent" at the end of the line that begins with "append", and save the file, so your syslinux.cfg should look something like this:default unetbootinlabel unetbootin kernel /ubnkern append initrd=/ubninit file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash persistent --For more info see https://help.ubuntu.com/community/LiveCD/Persistence