: Any "free" version of a license manager found on third-party sites is likely malware or a "crack" . These downloads often contain trojans or keyloggers that can compromise your data or lead to system instability. Recommended Actions :

: Adobe has removed CS4 from public download servers. Users must typically have their original physical media (DVDs) and a valid serial number to reinstall the software.

If you have a valid license, use the Adobe Licensing Repair Tool to fix existing installations.

Are you trying to on an existing CS4 installation, or How do I download the adobe cs4 suite? | Community