"It doesn't fuck up your system exactly, at least not in a guarenteed way. Think of it as an added layer of complexity in an already complicated system, it wiggles its way in - yet another thing that can (and does) cause crashes and random lock ups, another thing that has its own host of incompatibilities. That's just the technical issues, although starforce claims it works perfectly, it's yet another weapon in the war against piracy that screws only the legitimate customer.
That gives me no detailed technical information whatsoever about why you think starforce does anything to your system. God, everyone is so vague about this. Please, point me to a link that shows the technical problems with this copy protection.