updateing

Every time i click check for updates in settings it never finds an update and my phone was never updated to begin with ive tried the support tool but it wont locate my phone any ideas how to fix this?

when my phon c2-01 was updated then coming white screen and i was removing data cable from laptop and phon was dead power off

i got a iphone 4 and its on 4.1 but i want to update to the latest firmware will this change my baseban, please help thanks