Making a Live CD is downloading a .iso from the Ubuntu website [‘d use 12.04 32-bit as it’s most likely to work].
Then when it’s downloaded: in Windows, pop a blank DVD-R* in your drive, find your file, right click, and choose Burn Image to Disc.
That should give you a bootable DVD.
Start your PC – head into the bios first to set it to boot from DVD drive, then pop the Live DVD in and let it boot – you want the “Try Ubuntu without changing my PC” option. It is slow to boot from a DVD, but eventually you will land on the desktop. From there plug your external in, wait for it to mount and go grab your files to copy off.
You may need the laptop running to Google info about how to find your way around in Ubuntu, but it’s pretty easy.
*dismiss any messages when you put it in.