I have an older PC (Pentium) with about 1 GB RAM, but it does not have a DVD drive. I looked at the Ubuntu USB blurb on installing from a USB stick. But, when I went to the link for the pendriver install I didn't see what was clear to me how to prepare a USB drive to install the ISO image I downloaded . So, can any explain to me how I might do this? The target old PC does have an older Ubuntu version installed but thought I would attempt an updated version. I would like to really install 12.04 if I can get a USB loaded to try. If not, can anyone point me where to get an older (CD Live) Ubuntu install that I can use to generate a bootable/try ISO. Thanks.