You could also use Gparted - partitioning tool ( on normal or failsafe mode ) , it's just amazing !
You could do all the operations on manual( advanced mode), with Gparted you could even create the future EXT4 partitions on which you plan to reinstall Ubuntu, you need a / partition (I'd give atleast 20 GB ) a /HOME partition (or use the one you already have) and a SWAP partition( I would size it to 1 GB).
English being my third language I didn't noticed that you plan to dump Ubuntu :) . I had some issues with my toshiba laptop ( and the shitty i3 integrated everything) and previous ubuntu versions but I'm all excited about the new Ubuntu 14.04 and hope that the drivers would work better and my laptop would stop behaving like a fan :)