I installed 10-Preview on a lot of older PCs to see how they behaved. AMD 740-chipset motherboards with 4Gb work fine, 8Gb even better (these are Athlon XP, X2, Phenom X_). AMD 760s, 785s (Athlon IIs)... Intel Core 2 Duos, and even Pentium D's.
We also loaded old XP-era software - DVD Shrink was near the top of everyone's list - and that works the same, although we're wondering Microsoft's always-on tracking will give way to having those services shut down by Sony and the movie studios like DVDFab has been crippled. Maybe we shouldn't have installed DVDShrink and never let Microsoft know it's being used.