iPhone won't activate after restore. Activation server unavailable

There are two common causes for this problem:

1. Your antivirus or firewall is blocking access to gs.apple.com. Disable them and try again.

2. You once, at some time in the past, used your computer to hack or jailbreak some iOS device (not necessarily the iPhone with the problem). If you did your network database on your computer is corrupted, and you will have to edit your hosts file and delete any lines that contain gs.apple.com.

my firewall has always been off and I can't find anyfiles containing "gs.apple.com" anywhere on my finders search?

please help!

It's a hidden file, so it probably won't show up on a search. Instead just open /etc/hosts.