Most popular posts widget not working

I had a designer help me with my blog and am now overwhelmed by its complexity.

The three-in-one widget with Most Popular Posts, Most Recent Posts and Recent Comments works fine, with the exception of the Most Popular, which unfortunately has never worked.

Here’s the current code:

<div class=”sublinks”>
Most Popular
Comments
Most Recent
</div>

<div id=”cat_content_1″ class=”cat_content”>
<?php popular_posts(); ?>
</div>

<div id=”cat_content_2″ class=”cat_content” style=”display:none”>

<?php if (function_exists(‘get_recent_comments’)) { ?>

<?php get_recent_comments(); ?>

<?php } ?>

</div>

<div id=”cat_content_3″ class=”cat_content” style=”display:none”>

<?php wp_get_archives(‘type=postbypost&limit=5’); ?>

</div>
<div style=”clear: both;”></div>

Any suggestions?

I also don’t know how to back-up the dang thing and update to the next version of WP.

THANKS IN ADVANCE!

Cheers,
Jennifer