Using PC-X64 or PC for 64-bit Windows OS

[Puffy]

Hi, I have configured Hardware using PC for some of my 64-bit 2003 OS.

Is it recommended to change it to PC-X64 ?  

Thanks 

[J_H_Is_gone]

I have not been able to tell it that really makes a difference or not.

It is usefull to me when I go to do upgrades to know which ones are 86 and which or 64.

I would also like to know if anybody KNOWS that that setting makes a difference.