Elements 12 won't install

Elements 12 won't load automatically from either of my CD drives, both of which can easily read and display my own CD back-up files, so I'm concluding that the auto-run facility is OK. I have also tried, as an experiment, to read other makes of software from previous installations, but without success. I have checked the Elements disk on another PC and it loads without trouble, so it's not a faulty disk. When I load the disk into my PC and go to the drive in "computer" there is no content listed. I still have Elements 4 on the hard-drive. I tried downloading 12 from the web (whilst still retaining Elements 4) and, whilst the editing suite worked fine, the organiser came up with the message "A problem caused the program to stop working correctly. Please close the program". It was quickly uninstalled by me! My OS is Windows 7. This is very frustrating, any help will be much appreciated. HS.