Hello,
I've just checked my site using http://xxx.brokenlinkcheck.com, and found 569 broken links, mostly 500 and several 404.
I have no idea how to fix them manually or why are they considered "broken links"
I'll be very thankful if someone may assist me how to fix the errors, I am very novice in this field...
Here are 3 samples, the first 2 500 and the third 404:

(error 500)
<div class="navNextPrevList"><a href="http://w w w .petrutech.com/index.php?main_page=product_info&amp;cPath=5&amp;products_id=&amp;zenid=2650b8cf 94328282c9d06e62b188edd2"><img src="includes/templates/free_blue/buttons/english/button_next.gif" alt="Next" title=" Next " width="47" height="22" /></a></div>

(error 500)
<div id="askaquestionsideboxContent" class="sideBoxContent centeredContent"><a href="http://w w w .petrutech.com/index.php?main_page=ask_a_question&amp;products_id=58&amp;zenid=9fa48c591ea4cd2a ae4060be8fbe61c5"><img src="http://www.petrutech.com/images/question.gif">

(error 404)
<div class="navNextPrevList"><a href="http://w w w .petrutech.com/index.php?main_page=index&amp;cPath=5&amp;zenid=845581beb76507935a1a000c4ab4e7a9 "><img src="includes/templates/template_default/buttons/italian/button_return_to_product_list.gif" alt="Torna a elenco articoli" title=" Torna a elenco articoli " width="65" height="15" /></a></div>