When a CS4 trial version expires, or when a time-limited CS4 serial number expires, do the following to re-serialize the product:Trial versions: In the case of an installed trial version that has expired, the user can not use the product anymore and is presented with the serial number screen upon launch. Enter a valid serial number, so that the Creative Suite product gets serialised and the product is fully functional. Time-limited serial numbers: In the case of an expired serial number, the user can not use the product anymore and is presented with a license expiry message Licensing for this product has expiredupon product launch. In order to get a valid serial number to serialize the product, the user will have to do one of two things:
1. Un-install and re-install the Suite product with the new serial number.
2. Change the system date to an older date, deactivating the product (with erasing serial number option checked) and entering the new number on subsequent product launch.