And excactly on what system? Did you properly input the serial numbers and/or detected the CS5 install the CS4 install? You need to be more specific.
Close all Adobe application
Locate and remove cache.db files:
- On Windows XP and Windows Vista, the cache.db file is located in Program Files\Common Files\Adobe\Adobe PCD\cache
- On Mac OS X, the cache.db file is located in Library/Application Support/Adobe/Adobe PCD/cache
Re-open the app and enter the serial number and check.
Thank you - I got through to the help line and have it sorted....