Something about Windows 32bit and Windows 64bit's files

[LunaMoo]

Nothing is different.

Except maybe redistributable d3d11 shader compiler library, if you want to have both rename x86 one to d3dcompiler_47.x86.dll, installer should do that automatically. If you're on windows 10 and maybe also 8.1 you wouldn't even need those as they're part of modern windows installation.

I would advise against launching more than one PPSSPP at a time unless you keep separate ini files as they will share all of that when kept in same folder. Also no idea why would you want to keep different builds of same version, using x86 builds on x86_64 is like buying gluten free food without having Celiac disease aka convincing yourself to get pointless things just because they exist for other people that actually need them.;p