I installed ubuntu 12.04 (updated to 12.10) on a separate partition from inside windows 8 using WUBI. I would like to use only ubuntu. can I simply delete the partition where windows is located? btw I'm using the windows boot loader.
If you wish to get rid of Windows altogether, it is best to do a fresh install using a live USB or live DVD.
However if you wish to keep settings and applications already installed in Ubuntu you may consider migrating it.
This page explains how but in my opinion you're better off, backing up your data to an external drive and do a fresh install.