I was unable to install the dictionary on Windows 8.1. I sent a message to [...] the company that distributes the program. After I replied that they had had no difficulty to install the program on their own computers with Window 8.1 (a comment that helps me a lot!), They still said that some other guests had had the same problem Only me. They gave me a link to download the contents of the CD and install the program from the hard disk. After several attempts, it still does not work ..... I think to return the dictionary Amazone.fr.