i'm afraid you will have to download it from microsoft.
somewhere
here for the web install of Windows Server 2003. you can also download an
ISO or the
whole archive.
and
here is the web install for the Vista SDK.
i don't know if CVI 8.5 comes with an updated SDK, but i think it would be great since, as you noted, windows 2000 is getting quite old and outdated. also, the html help (.chm) file of the windows SDK distributed with CVI severely lacks the "content" tab as well as a good index and search feature. note that those features exists in the SDK linked above.