This is the code:

nstall security images form code in existing Joomla code...
point A 	Open components\com_registration\registration.html.php line 54 in function registerForm($option, $useractivation)
  	<tr>
<td>
<?php echo _PROMPT_EMAIL; ?>
</td>
<td>
<input type="text" name="confirmEmail" class="inputbox" size="40" />
</td>
</tr>

<?php
//security image by www.waltercedric.com
global $mosConfig_absolute_path;
if (file_exists($mosConfig_absolute_path.'/administrator/components/com_securityimages/patches/registration.lostPassForm.php')) {
require_once($mosConfig_absolute_path.'/administrator/components/com_securityimages/patches/registration.lostPassForm.php');
}
//end security image by www.waltercedric.com
?>

<tr>
<td colspan="2">
<input type="hidden" name="option" value="<?php echo $option;?>" />
<input type="hidden" name="task" value="sendNewPass" /> <input type="submit" class="button" value="<?php echo _BUTTON_SEND_PASS; ?>" />
</td>
</tr>
point B 	Open components\com_registration\registration.html.at line 164 in function registerForm($option, $useractivation)
  	<tr>
<td>
<?php echo _REGISTER_VPASS; ?> *
</td>
<td>
<input class="inputbox" type="password" name="password2" size="40" value="" />
</td>
</tr>
<?php
//security image by www.waltercedric.com
global $mosConfig_absolute_path;
if (file_exists($mosConfig_absolute_path.'/administrator/components/com_securityimages/patches/registration.html.registerForm.php')) {
require_once($mosConfig_absolute_path.'/administrator/components/com_securityimages/patches/registration.html.registerForm.php');
}
//end security image by www.waltercedric.com
?>
<tr>
<td colspan="2">
</td>
</tr>