Hello!

I have a strength problem - I have add IUSR full access to all file and folers belod "Data" but every time I upload a file or a image I have to go to that file and give it correct secutity settings.

What am I doing wrong?

Struggled with this issue for a little while before stumbling on to the solution. Files uploaded through the file manager will not be accessible on a non-authenticated page because IUSR does not have read access rights.  You may see the file while logged in as Admin but not accessible after you logout.

FIX : 

In IIS 7.0 ... If you are using Network Service in the Process Model in the AppPool. 

set LOAD USER PROFILE  to TRUE

"This setting specifies whether IIS loads the user profile for an application pool identity. When this value is true, IIS loads the user profile for the application pool identity. When this value is true, IIS loads the user profile for the application pool identity. Set this value to false when you require the IIS 6.0 behaviour of not loading the user profile for the application pool identity."

Hope this saves someone else from a few hours of frustration.