SEARCHHOTKEYS: An extension for Firefox that lets you modify or disable the keys that open the findbar. Usually these keys are ‘ (for search only in links) and / (for normal search).
Right click on the link for the appropriate version of Firefox then select Save Link As…
Once the extension has been saved locally use the Open File… or Ctrl-O in Firefox to open the extension.
Browse to where the extension has been saved and then click Open. A confirmation dialog box will appear, once confirmed the installation will begin.
Firefox will need to be restarted to complete the installation.
http://www.nic-nac-project.org/~kaosmos/index-en.html#searchkeys
Useful Links 