If you want to open a .aoi file on your computer, you just need to have the appropriate program installed. If the .aoi association isn't set correctly, you may receive the following error message: Windows can't open this file: File: example.aoi. To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select from a list of programs that are installed on your computer.