each time I start Construct application its window is automatically maximized/resized in full screen. OK, then I can resize manually the window, but isn't possible to let the application in a standard size so that the user decides if to go in fullscreen? Or better, when the user close Construct in a certain window size and position and then restart it, Construct is in that size and position.
Go to projects on your lower right corner, then in the upper right click Application 1
if you look at the panel to your left, thats where the resolution and whether app will run maximized or full screen settings are.
if you want to let player choose that stuff, you can use events. This tweaks are under "System" object.