[ubuntu] Messed up a password, now can't install applications.

view story

http://ubuntuforums.org – (Bear with me, linux-noob here) Using Ubuntu 12.04 on a fresh install. I had gone into the User Accounts, unlocked, set no password with auto-login. Also went to Passwords, changed pass on the default keyring to be blank and selected Use Un-Safe Storage. These ( aside from cosmetic ) are the only changes I have made. Now I'm going through the software centre to try and install something, it asks me for a password, I have no password to put in, if I leave it blank it won't accept it and if I put the password I set for my user during installation, it won't take it either as I had cleared i (Hardware)