CDO default for OL2007 under Vista?

Hi,
I’m looking for Collaboration Data Objects CDO for OL2007 under Vista. I found that CDO is not included in the installation cd anymore.
What I would like to know is: where and how can I obtain this software that will work together with OL2007 and Vista?
I found a Microsoft download site, but it was stated to be suitable for XP only.
Does somebody know where to find this software, or don’t I need CDO, because it is incorporated in Vista already? How can I find out about this all?
TIA