passworded bios, modded case extend mod a power button that goes in and out of like maybe a combination safe and lock the computer inside so people cant reset the bios or format the computer.
Install loads of security software. 24/7 monitoring of network packets. Setup security cameras. Take insane safety measures. Forget to lock the door... That's how it almost always happens
reminds me of a guy that brought his computer in and swore that "hackers" were getting into his computer, (he had some spyware), but kept on telling us of all the "hackers". I had to byte my tounge, after all, if your'e a "hacker" why would you hack into an 80 year old man's machine. I assured him that he had no "hackers" infiltrating his machine, but he stuck with his story no matter what i told/showed him... "hackers"