The live CD needs about 256mb RAM. You can download the alternate install CD and install from that. It is a text based installer that is very similar to a Debian install CD. Get the alternate install CD here:
Choose a mirror for your country, check the box for "alternate install CD" and download that to install. You will have to burn the .iso to a CD. Here are instructions for burning an .iso from windows if you don't already have linux installed:
You might also consider Xubuntu. It is the same as ubuntu except it uses xfce desktop instead of gnome, which is a bit lighter in computer resources. You can find Xubuntu by clicking on any of the ubuntu mirrors. Write back if you need more help.