Installing another OS on a 2nd Hard Drive

I just recently installed Windows Vista, but I would like to reinstall
Windows XP Media Center on my 2nd Hard Drive. I understand how to install XP
on the 2nd Hard Drive, but I do not know how to switch between the two
operating systems. Can anyone explain how this is done?

To create a dual boot system the rule is "oldest OS installed first" -
reason of compatibility between OSs.
XP must boot from an active partition on drive 0 (Usually C)- a boot manager
is necessary to boot XP from another partition.
There have been several posts dealing with the same subject - with solutions
offered.

"Huron_Desolation" <Huron_Desolation@discussions.microsoft.com> wrote in
message news:9C71A666-A1A4-4C45-86E1-E5472A9F4B17@microsoft.com...
>I just recently installed Windows Vista, but I would like to reinstall
> Windows XP Media Center on my 2nd Hard Drive. I understand how to install
> XP
> on the 2nd Hard Drive, but I do not know how to switch between the two
> operating systems. Can anyone explain how this is done?