Re: Error codes 1921 and 1603

See:

Exit Code: 6, Exit Code: 7 Installation Errors -

http://helpx.adobe.com/creative-suite/kb/errors-exit-code-6-exit.html

Error 1603 | Install | CS5 products : 

http://helpx.adobe.com/creative-suite/kb/error-1603-install-cs5-produc ts.html

For the 1921 error search Google using "Error 1921" and see if you find a solution relevant to your OS