How to hide/remove "Request New password" link in Drupal 7?
this will remove it from the render array before it is printed. In your theme's template.php, add:

function MYTHEME_form_alter(&amp;$form, &amp;$form_state, $form_id)
{
    if($form_id == 'user_login_block')
    {
        $form['links']['#markup'] = '&lt;div class="item-list"&gt;&lt;ul&gt;&lt;li class="first"&gt;&lt;a href="/dev/user/register" title="Create a new user account."&gt;Create new account&lt;/a&gt;&lt;/li&gt;&lt;/ul&gt;&lt;/div&gt;';
    }
}


Basically, it is just rewriting the markup for the links in the user login block. You can tweak this to theme as well. this should only apply to the user block