I've been trying to install Ubuntu 12.04 (32-bit) as a dual boot on my laptop which is running XP. I managed to create a bootable USB stick, and to boot the laptop from that. When offered the choice between "Try Ubuntu" and "Install Ubuntu" I first chose "Try" and was able to try out various features of Ubuntu. So far, so good. Then I started again, this time choosing "Install Ubuntu", which gave me only two choices: either to Replace XP by Ubuntu (which I don't want), or to do "Something else", which sent me to a screen which seemed to be requiring me to partition the disc. This is no good for me because I know very little about partitions, and anyway don't know how to use this rather enigmatic screen. I note that the example on the "Install Ubuntu 12.04.4 LTS" web page suggests that (a) the "Something else" choice is for advanced users (clearly not me!), and (b) there should be a 3rd choice: "Install Ubuntu alongside Windows" (which I assume will create a partition for me). How do I get access to this third choice? Any other suggestions?
The hard drive is 149 GB, with 103 GB free space