FYI...i ve a genuine version of vista ultimate waitin to install it tho

Did lots of googling:

goin for the 32bit by the way. I see nothin going for the 64bit version right now based on my usage. future change, who knos. Right now, all my apps are 32bit, and i use nothin that requires that much memory to go >2Gb

Found some useful info:
sysops at that link has links to some useful articles on the topic.