Since we are talking about mental illness I know reason isn't going to work here. Does it have to be this machine? Does he really just want win XP? Maybe there is an XP emulator out there that is safer.
Mental illness, brah. He focuses on things that are difficult to obtain.
"I want a VHS to watch my dvds"
"You can't do tha..."
*screams for 10 years, attempts suicide etc etc*
So we eventually buy the hardware to record DVDs onto VHS tapes and let him watch that grainy shitshow. The response is, "That sucked." And it's onto the next thing.
The XP thing is fairly tame, but i don't want to spend more time or engery on it than i have to. I want a path and a slow drip execution that will delay the next shitshow.