September 18th, 2016, 15:36
It all has to do with folder permissions. When you install FS9 to the default location, you're installing into a highly protected directory that tends to reject changes and restore previous file versions for your protection. This is something that started with Vista and continues through 10. The only real cures are to grant yourself full admin rights to the FS9 root folder and all files/subfolders, or to begin by installing to a location outside the "protected zone." I have a folder on the root of my C drive called Added Programs that contains my FS9 and a few others, like Gimp and Notepad++.