Can I restrict users to see only the dialog window to search their hard drive when uploading images (I mean I don't want them to see the images folder on the server).
By right the built in Editor would not show server side items when a user tries to upload an image so it could be that you are using a different editor that works differently.
Is it possible for you to provide us with the back end and FTP access to your site to check on this issue?
You are most welcome. Glad to hear that your issue has been resolved now.
As a gentle reminder, kindly start a new thread if you have any other issue in the future so it will be easier for us to manage your inquiry. I will lock and mark this thread as resolved.