Hi i'm currently using a pentium 4 630 with windows 8.1 32 bit but will soon be upgrading to a pentium d 945 dual core cpu and my question is which windows is best for that cpu besides win xp? is windows 8.1 32 bit best choice or is 10 better? i also used win 7 64 bit on this pc but wanted to give win 8.1 a shot. Its running pretty well on the current cpu is 10 better or is 8.1 better?