It takes a hardware fingerprint of the entire PC, much the same as Windows does and looks for specific vendor information/serial numbers. If enough serial numbers match, it decides that the machine is blacklisted and denies it access to the Server.
(, Fri 8 Nov 2019, 9:58, Reply)
Seem to recall its possible to manipulate those used when browsing
(, Fri 8 Nov 2019, 18:04, Reply)