arm still needs a custom kernel and conpletely different drivers to even boot, because every manifacturer can implement it completely differently.
Dunno why you’re getting downvoted, this is correct. ARM makes comparatively very expensive to maintain an OS over a variety of CPU models. The specialization required by each Cortex revision (and beyond that, each manufacturer adaptation) is too intense for a world trying to conserve resources.
x86 hardware is standardized in a way where you don't need to port an os to them, it just runs with generic drivers.
That being said, I’m honestly shocked your friend doesn’t run into issues. Several ISA extensions have been released for x86 since the Core 2 Duo days, and I have to imagine software incompatibilities appear semi-frequently. Running Windows 10 on that can’t be a good experience.