How can i disable user from downloading my picture or file from my link : spenceryong.com
Not at all. That's the point of running a site. That's how a browser works.
However, as suggested in the other open thread you have: there's little to steal from your site with only one public image, so what are you afraid of? As suggested in the other thread: burn your pics to a CD and send a copy to all your friends, especially if you're afraid that people might steal the images.