If you have any questions on how to run the uninstallers or how to download and run the CC Cleaner Tool then please update this forum discussion. Otherwise please follow the steps offered by Kglad in message #9 Barrettb64394936. Once you have applied any available Windows 7 update you should then be successful with the installation of Creative Suite 3 Master Collection. If this is a fresh installation of Windows 7 you could skip Kglad's suggestions, in message #9, and reformat the computer. If the serial number is not being accepted then it is due to an inability to update the necessary licensing files or the licensing files exist but are corrupted. In answer to your question Barrettb64394936 the serial number validation process occurred when you were provided the download at Activation or connection error when starting CS3 or Acrobat 8. Kglad is very experienced member of our community and is trying to help you. Barrettb64394936 please continue to respond in this public forum discussion.

Cs3 master collection