Windows XP Professional x64 Edition supports up to 128 gigabytes (GB) of RAM and 16 terabytes of virtual memor
I don't forseen us having 128 GIGABYTYES of ram in our PCs any time soon... Considering the largest interla HD yhou can have today is like 2.8 terabytes (thats with 4 750 GIG HDs which would cost a lil bit over 2,000 to own) 16 terabytyes of virtual memory isn't very likely. However 64 bit does increase proframnce.
in about 13 to 15 years is when 128 GIGs of RAM will be about, and teh 16 terabytes of virtual memory I predict that'll be slighlty useful in 10 to 12 years. So um, you can still run on your 32 BIT CPU for the next 10 to 15 years. Even if you bouhgt a 64 BIT CPU today for only that reason above, you'd of thrown it out LONG BEFORE THEN.