[TYPO3] Indexed Search: How to uncheck Extended Resume

[Theo]

By default Indexed Search shows results from page content plus keywords because 
the Search Form shows:
<input type="checkbox" value="1" name="tx_indexedsearch[extResume]" id="tx_indexedsearch_extResume" 
 checked="checked" />

I have searched everywhere but can't find a way to uncheck "tx_indexedsearch_extResume" 
so that results displayed are only those from content and not tags.

Any help?
Thank you