how to set address bar to search google

Type about:config in address bar of Mozilla Firefox.  You must confirm you know what you're doing.
Type keyword.URL in filter box.
right click on the preference name and hit Modify
paste this into the box that opens:  http://www.google.co.uk/search?btnG=Google+Search&q=
Now Type browser.search.

defaultenginename in filter box
right click on the preference name and hit Modify
paste this into the box that opens: Google