PC Tools officially retired its products years ago. Even if you find a valid license key, the software often fails to "call home" to verify the license, meaning the software stays in trial mode.
At the time, it was far less "bloated" than competitors like Norton or McAfee. The Problem with "Top" License Keys pctoolsspywaredoctor9102900withantivirus key top
Are you trying to install this on a or an older legacy machine for a specific project? PC Tools officially retired its products years ago