the cuestion is becoues I want to change my PC (P4 3.2 for Core 2 Duo or Quad Core).
and I don't want to change XP for Vista. if there are diferences on development between them.

the same with DDR1 and DDR2 667 or 1066.

it's necesary an SP 3 or something like that.


and I have a Laptop Dell Precision M90 with vista and I don't like how it runs.

XP can support multi core but don't you need the 64bit version? SP2 can also support multi core.

In fact even XP home will support quad core without scalable support and I don't think you need the 64bit version but not 100% on that fact.

are you saying that Xp 64bit is better than 32bit version in this special case?

Obviously in the future when all applications are 64bit then yes x64 is better than 32bit. Check out this debate:- http://news.softpedia.com/news/Are [...] -500.shtml

For now most apps are still 32bit so advantages are not apparent and you would still have to run 32bit apps on XP 64bit. I have just found you can run the 32bit xp on a dual or quad core processor.

in conclusion....

I can have a Quad Core or Centrino Duo (Laptop), DDR 3, working with Xp 32 or 64bit until nothing better comes on OS for the moment.

thanks