My failed ubuntu 14.04 upgrade

While upgrading from ubuntu 13.10 to 14.04 I accidentally pressed back the back button in a step when asked for creating a username. My installed ubuntu OS crashed. Luckily i backed up my data from it before upgrading. So nothing was lost. Don't worry, the install later worked properly when i tried properly. But you guys be careful and take precautions while installing it and don't forget to backup data first.