@trinsec
Wow, that old. You can get an adapter for it. I think that it's worth it purely for the access times and reliability.
Wait, I just realized. If the games he wants to play run in DosBox, installing XP is useless, because they won't run natively on that either.
You should install Win 95 or even older.
@matrix Actually, XP is fine with DOS. It's beyond XP that it starts not to be fine with DOS and where you need DosBox. We use DosBox on his Win10 machine. And I'm seriously not going to suggest spending money on an ancient piece of crap with a thick nicotine layer. Ugh.
@matrix Though the idea of Win95/98SE isn't a bad one. I migth have a CD of that lying around still. But I'm really not in the mood to go over there again for a whole day just to install old shit and then have to dump my clothes in the laundry afterwards because the house's reeking of nicotine. :P Maybe in a month or so. :P
@matrix XP and old computer, no SATA capabilities, so we needed a PATA one. Old crap.