Install CS 5.5 impossible after format PC W7Pro

Hi,

I had to format the PC (I used Recovery on the Dell Optiplex 990 with Windows 7 Pro)

Then I cannot re-install CS 5.5, the error message is "L'initialisation du programme d'installation a échoué." (Installation program initialisation failed)

This error message comes just after I launch the Installer.

Any ideas ?

Thanks

Manuel