Need help restore iPhone 4?

I need help restoring my iPhone 4
I traded my milestone for iPhone 4 today
because iPhone was jail-broken already, when I reset the phone it stuck at apple logo (which I was expected)
I came home try to restore, it start giving me error (error 3194)
I searched for information on Google… uninstall all apple related stuffs (including drivers, iTunes) still not working
host file does not exist on my driver folder
I don’t know what to do now

I want to restore without upgrade so I can unlock the phone to use
anyone got idea?