Why some of web page can not be saved in my computer?

Answer 1

Webmasters also use web page protection utilities to prevent people from saving pages.

I've seen this on photo sites where the user doesn't want people using their photos without permission.

Sometimes you can tell a site uses these methods as when you right-click, you don't get any options or if you view the page source, it's encrypted

Answer 2

you can't save flash, or realmedia files, and sometimes code is blocked from downloading