I have created a home page component Image type. I have selected image from document folder, and now it is showing as a hard coded id, How I can avoid this hard code id .
Are you are asking on how to hide the Body tag inside the Home Page Component? then the answer is you cannot edit the layout of Home Page Component
You can only edit the Home Page Layout using the Number of Home page components
You can only assign links, image, etc and can add them to Home Page....
The image you have posted is of the Home Page Component's detail page which is defined by SFDC. If you want to add this component to the home page layout, you have to go
Setup-->Customize-->Home-->Home Page Layout
and add the component to the layout(Check the checkbox against the component).
In case, you want to view what the image is, you can directly go the image URL which is specified in src and see it.
Hope this helps.