Which version of itunes should be used to upgrade an iphone to 5.1.1?

I want to upgrade an iphone to 5.1.1 which is working on 4.0.1 currently, when i tried to restore it using lastest itunes it is giving me such annoying error "3194", please guide.

You can directly update your IOS from iPhone setting, it is not necessary to update from Itunes.

If you want to update from itunes, here is the the latest itune
http://www.apple.com/.../download/