First computer i used for my iphone was my girlfriends mac, then i came home and to start apps and twitter from my computer and it is linked to her user name and so on....So i obviously need my computer to be it's home computer and i'm trying to figure how to reset that.
So i had figured that out when sync from different macs, so i reset the music and everything else from itunes to link it to this computer. But outside of itunes, it's still linked to her computer/user names.
Settings/Store. Log out, then log in with your Apple ID. Note that any content acquired through her Apple ID will always be associated with her ID. So you will not be able to update apps or restore any iTunes purchased music without her ID and password.