ELAN creates a special folder to store settings, preferences and configuration files and to cache content downloaded from internet. The name and location of this folder depends on the operating system:
on Windows: <user_home>\.elan_data
where the <user_home> folder resolves to (depending on the Windows version) something like C:\Users\user_login_name
on Linux: <user_home>/.elan_data
where <user_home> is just the user's home folder
on Mac OS X: <user_home>/Library/Preferences/ELAN
where <user_home> resolves to /Users/user_login_name. To access the Library folder in the Finder you can hold down the Option (Alt) key when clicking the Go menu. Library will then be visible in the list.
Apart from that ELAN expects to find specific files and folders in its installation folder.