How CPA tracks if installation is complete?

I'm looking into CPA (awm) and I see they offer sort of PPI. But I wonder how do they track the certain software has been installed? Through IP or what... would the install been recorded if I'd download the software and then install it on another PC without visiting the landing page and then downloading from there...

Thanks.

I guess the ip will be sent to the server when you install the software. They compare download ip and installation ip....