Change Tag Pages To Show Full Post (Not Excerpt)

Do not edit the Twenty Ten theme. Create a child theme for your changes. Once your child theme is active, we should be able to help with the customisation.

I should have mentioned I am already using a child theme.

In that case, you need to add a loop-tag.php template file to your child theme based on the parent’s loop.php file. Just keep the 3rd Loop and remove the <?php if ( is_archive() || is_search() ) condition.

I removed:

<?php if ( is_archive() || is_search() ) : // Display excerpts for archives and search. ?>

But I get a syntax error

Here is what I see around the condition you specified:

<?php elseif ( ( function_exists( 'get_post_format' ) && 'aside' == get_post_format( $post->ID ) ) || in_category( _x( 'asides', 'asides category slug', 'twentyten' ) )  ) : ?>
<div id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<strong><?php if ( is_archive() || is_search() )</strong> : // Display excerpts for archives and search. ?>
<div class="entry-summary">
<?php the_excerpt(); ?></div><!-- .entry-summary -->
<?php else : ?>
<div class="entry-content">
<?php the_content( __( 'Continue reading <span class="meta-nav">?</span>', 'twentyten' ) ); ?>
</div><!-- .entry-content -->
<?php endif; ?>

[Please post code snippets between backticks or use the code button.]

Should I be removing more than what i did?

Try https://pastebin.com/VsmirK4w
Warning: untested.

Dreamweaver was giving me a syntax error on line 33 (from the code you provided above).

33. <?php endif; ?>

Once I removed that line from the above code it works great.

Make any sense to you? I know nothing about php.

It is working so I will go with that unless there are any other suggestions you have.

Thanks so much.

Joe