cheers!! Vista s relzn on jan30 wat bout halo 2 vista

what is the actual name of vista .
i have heard many names like vista rc1, vista home, vista ultimate etc.
can i install vista with windows xp

These are different "flavors" of vista.Each have their own features.While rc1 is the release candidate which is the final stage of software development before its actual release-see here *en.wikipedia.org/wiki/Development_stage and check this out for information about vista flavors *www.microsoft.com/windowsvista/getready/editions/default.mspx
If your hardware supports it you can run it with xp, just like we can run win xp with win 2000.