Set Firefox Google Search in English

This tweak allows you to set Firefox Google Search in English independently from your computer language settings and your location and allows you to clear cookies in Firefox 3+.
This tutorial is valid for Windows Operating System with Firefox 3+.
It is likely that this also works on other Operating Systems and/or in older Firefox versions than 3.
To set Firefox Google Search in English you need to modify the file “google.xml“, part of the Firefox installation.
First of all, close every Firefox instance.
Open the folder "C:\Program Files\Mozilla Firefox\searchplugins\" by clicking Start, then Run, in the Open box type the folder path and then click OK.
Copy the already present file “google.xml” to “google1.xml” in the same directory "C:\Program Files\Mozilla Firefox\searchplugins\".
This is to keep a back up copy of the original Firefox installation, in case you need to revert back to it.
Open the file “google.xml” with Notepad.
It would look like this “google.xml” but the long key string for the "Image" tag is different for every Firefox installation.
Add this statement: “<Param name="hl" value="en"/>” to the “Param” list
Save the file “google.xml” in the folder "C:\Program Files\Mozilla Firefox\searchplugins\" and close it.
Restart Firefox and see the results.

(thanks to Zia: http://www.zialingua.com/bbs/2008/10/14/how-to-set-firefox-google-search-in-english/)