Also in Windows File Explorer, if you right click on a file and open the 'Properties' information, you can go to the 'Info & Preview' tab and it should show you the Archicad version it was saved with.
Also in Windows File Explorer, if you right click on a file and open the 'Properties' information, you can go to the 'Info & Preview' tab and it should show you the Archicad version it was saved with.