Currently Being ModeratedFeb 12, 2013 1:11 PM (in response to Evil Cod)
Check this support document http://support.apple.com/kb/TS3694. 3194 generally means an issue with software build. Make sure you are running the latest version of iTunes, then try and restore the device. Error 21 mentions security software, so you need to check the support document for help.
Currently Being ModeratedFeb 12, 2013 1:14 PM (in response to Evil Cod)
Those 2 errors most commonly occur if your antivirus blocks access to gs.apple.com or if your phone is jailbroken or hacked. If it is you cannot get help in an Apple-hosted forum. If it is not try disabling your antivirus and firewall.
The only way the hosts file would be corrupted is if your computer was used to hack or jailbreak some iOS device, not necessarily the phone with the problem.