ERROR "Licensing for this product has expired" =

Caused by not setting your host file, previous trial has expired or previous
version has left key in registry.

Soloution 1;

Go to the HOSTS SET-UP folder and follow the steps there.

Solution 2;(try A then check app then B then check the app then C);

A Do steps in the ADOBE LICENCE RECOVERY TOOL.

B 1. Delete;
     Program Files CommonFiles Adobe Adobe PCD 
     Program Files CommonFiles Adobe caps 
     Program Files CommonFiles Adobe backup 
  2. Restart app and enter a serial.

C Do the steps in CS4 LICENCE RECOVERY folder (LICENCE METHOD 1).

Solution 3;

Go to the CLEAN INSTALL folder and follow the steps there.