Google search has the autocomplete suggestions integrated to it for quite some time now and is really useful to the users too. However, some 
users find it irritating as one of my friend complained about it today too.
In this post you will be knowing how to turn off google autocomplete suggestions.
How to turn off Google suggestions
Well the process is fairly simple, you can edit preferences for your google experience. But you need to have logged into google.com (by gmail or google id) so that you can edit the preferences.
Once you have logged into google, goto: http://www.google.com/preferences and change the settings for Google Instant (select Don’t use Google instant – to turn off text predictions)