Block overriding with template file doesn't work
To Alter User login block


Find the template.php file for the theme you're working on. Should be in the root of the theme folder for your theme
Assuming the "yourthemename_hook" function does NOT exist, at the bottom of your template.php file insert the following code:



function yourthemenamehere_theme(&amp;$existing, $type, $theme, $path) {
   $hooks['user_login_block'] = array(
     'template' =&gt; 'templates/user-login-block',
     'render element' =&gt; 'form',
   );
   return $hooks;
 }
function yourthemenamehere_preprocess_user_login_block(&amp;$vars) {
  $vars['name'] = render($vars['form']['name']);
  $vars['pass'] = render($vars['form']['pass']);
  $vars['submit'] = render($vars['form']['actions']['submit']);
  $vars['rendered'] = drupal_render_children($vars['form']);
}




Now create a directory inside your theme's directory called "templates" (assuming it doesn't exist already)
Then create a php file inside that folder called: "user-login-block.tpl.php"
Inside this file, put the following code:



&lt;div id="user-login-block-container"&gt;
  &lt;div id="user-login-block-form-fields"&gt;
    &lt;?php print $name; // Display username field ?&gt;
    &lt;?php print $pass; // Display Password field ?&gt;
    &lt;?php print $submit; // Display submit button ?&gt;
    &lt;?php print $rendered; // Display hidden elements (required for successful login) ?&gt; 
  &lt;/div&gt;
  &lt;div class="links"&gt;
    &lt;a href="/user/register"&gt;Create an Account&lt;/a&gt; | &lt;a href="/user/password"&gt;Forgot Password&lt;/a&gt;
  &lt;/div&gt;
&lt;/div&gt;




CRITICAL STEP as an admin on your website, navigate to "admin/config/development/performance" and click "clear all caches" -- if you don't, then these changes won't display on your website
Modify the html markup inside "user-login-block.tpl.php" to your heart's content, and don't forget that you can also add those css classes to your main style.css file (AFAIK)