Properties, Start/Exit options
You can set the start folder for IrfanView.
Only 1 instance of IrfanView is active: Unchecking will allow the viewer to open more than once at the same time. Checking the box will prevent more than one instance of the viewer at any time.
Start in full screen mode: Show the full screen window, when you load an image in IrfanView. Then pressing ESC exits the program and not the full screen mode.
Warning on ESC exit: Check it, if you want to get a warning message, if IrfanView should be closed using the ESC key.
Ask to Save Changes on exit or file/image change: Check it, if you want to get a warning message, if IrfanView should be closed (or image/file changed) and an Undo or unsaved image is available in memory.
Close viewer only on ESC, if Thumbnails displayed: Check it, if you want to hide main IrfanView window on ESC click in it, if Thumbnails window is showed.
When you are done making your selection, click OK. To exit without any changes, click Cancel.