Win XP 32bit nemoka naudot daugiau nei 3GB RAM ir ne daugiau, nei 2 
procesoriu, nepriklausomai nuo coru:

XP Professional

If you want to use two processors, Windows XP Professional is the way to go. 
While this advanced program cannot run more than two processors, this is an 
improvement over Home. Note that, because dual-core processors count as a 
single processor, you could theoretically have four cores with this license 
or even eight, if you are willing to buy two quad-core processors.

I suggest you to visit this below provided Microsoft KB article.

Processor and memory capabilities of Windows XP Professional x64 Edition and 
of the x64-based versions of Windows Server 2003
http://support.microsoft.com/kb/888732



http://answers.microsoft.com/en-us/windows/forum/windows_xp-hardware/multi-core-processor-and-multiprocessor-limit-for/abd0a0ce-4ac2-484b-88cb-fbf93beb54e0


> winxp nemoka daugiau 2gb ir 2core naudoti
> win7 moka ir naudoja