To Enable Site Wide Search:
Click on each section to expand for further information
Under 'Master Settings' choose 'Search Settings'
In the 'Site-Wide Search' field select 'Enable Site Wide Search' from the drop down box
In the 'Site-Wide Search Area' field click each box for the portion of the site that should be included in the site wide search:
Content - Content Pages
New Forum - If you are using the new CFMBB forum style
Old Forum - If you are using the old legacy forum style'
Cart - If you are using the shopping cart, this will search the product pages.