Flash ScreenSaver Master supports .scr , .exe and Installer as its output file.
.exe is the standard file type for Winodws applications. It can be executed when doubleclicked. But you can only overview the screensaver by this file. Screen saver can not be installed from .exe file.
.scr is the standard file type of Windows screen savers. It can be executed when doubleclicked and has more options when right_clicked. For example, you may right_click on a .scr file to set it as system screen saver.
Installer is the file for directly installing the screensaver. Doubleclicked will lead you to install the screensaver. It will generate a .scr file as well.
Braveworld Networks
http://www.flash-screen.com/screensavermaster/