If the image is not loading, it will be one of two things:
1) You must have the GD library loaded in your PHP configuration with FreeType support
2) Permissions issue. In most cases, all directories should be 755 and files 644. Verify this. Also, modify the permission for this file to see if it fixes your issue:
/components/com_dtregister/captchasecurityimages.php
I can not get my security images to show. It is enabled in DT Register configurations and my permissions are correct. When you say to have the GD library loaded in your PHP configuration with FreeType support I am at a loss as to what to do exactly. I am not a programmer and need specific directions please. Thanks for the help.