older cpus were 32 bit processors. most current cpus are 64 bit processors. theoreticly, this means they are moe powerful. to fully access this extra power you need to have a 64 bit operating system, and the 64 bit versions of said programs.

there is no problem with having 64 bit hardware, and running 32 bit OS and software on it. the support for 64 bit is patchy with some programs.

 i think what you are looking at there is the maximum ram usage under XP yeah? if so, dont worry about it. i cant imagine what you would need more than 4 gigs of ram for, for quite a while. by the time you actually need it, you will be upgrading to vista anyway.

as re; operating systems, i use my old 32 bit version of XP pro. its the only one i know, so i cant advise one way or the other between xp32 and xp64.  i doubt there are many differences that would be very relevent to your current usage needs.

hope this helps.  

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