1.I have protected my administrator directory of joomla with a user /password.Whenever I open the library in the frontend,it asks for the administrator folder user/password.though after clicking cancel and without entering any user/password,the page continues to load.but this is very irritating for the users.
Yes - we use some common files from booklibrary admin part. Please open below folder
2.even after enabling ebook download option in the backend,i cant see any link to download ebbok in the frontend.
Sorry for me all work good. can you give to yours site admin account - with that we will can check where error. Admin account you can send through this site "Contact form"
3.I want the library to be private,accessible only by the registered users.but any user is able to access my stored ebooks directly if he knows the ebook link,even without logging.
When you create some menu item in "Menu manager" to BookLibrary - please set for it "Access Level" to "Registered" and all wor you will work