I'm having the same problem...
2011-03-13 16:12:14.731 [300:fc8]: iTunes: Restore error 3194
Did you follow the advice already posted several time in this thread to disable ALL security apps (firewall, antivirus/spyware) running on your PC?
+"Error 3000-3999: (3002, 3004, 3013, 3014, 3164,
3194, and so on) Error codes in the 3000 range generally mean that iTunes cannot contact the gs.apple.com server on ports 80 or 443. This may be because out-of-date or incorrectly configured *security or firewall software is interfering*, an entry in your hosts file redirecting requests to gs.apple.com, or due to your Internet proxy settings. If you are using a proxy, try without using one or with a known-good network. If that does not resolve the issue, follow iTunes for Windows"+
http://support.apple.com/kb/TS1275