@ parts : i plan to keep it Windows XP (Corp. Edition),...... i'v tried and played with Windows Vista (i actually have a laptop that has Windows Vista) and im not excited and impressed about it.
(i said the exact same thing when i had Windows 2000 and Windows XP had just came out,...... so i might eat my words in the future)
so lets say i had everything ready,...... and i had 4x2GB RAM,......would Windows XP recognize 8GB of ram

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@ simoko : thats the plan,..... upgrade to a AM2+ MOBO (not the AM2 MOBO with a updated BIOS so it could run AM2+)
i think im gonna stay away from NVidia GPU,...... i wanna keep it AMD/ATi (unless some can give me a real good reason to stick with NVidia GPU)
can i run my NVidia GPU on a AMD/ATi Chipset

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regarding the MOBO,..... can some suggest a reall good AM2+ MOBO that can run DDR2 1066 (or better)