He have look at http://store.steampowered.com/app/204880/?snr=1_4_4__105_1 , but he have read it in the wrong way... it is writen "Pentium 4 3ghz processor" and not "Pentium 4.3ghz"...
For memory, the P4 is the old 32 bit single core from 2000... these was followed by the Pentium D ... who itself was followed by the Pentium Core 2... and the most recent are the Pentium core i3/5/7...
Since , we have mutlicore, hyperthreading, x64, SSE4, Nx, etc...
As for XP SP3 on the steam page, it work with XP x64 SP2 without problem ( XP x64 have no SP3 )