If you've already partitioned your drive, then just select the first one. If not, create a single partition for XP and leave the rest of the drive empty; you can create the other partitions as you install the other operating systems.
After XP has installed, the next operating system to install is Vista. Perhaps in anticipation of some of the compatibility problems some users experience with Vista, the installation routine for Microsoft's latest operating system will automatically recognise an XP installation, and configure the Windows Boot Manager to add a menu at boot time to select between the two.
You will still need to use the manual option for installation in the Vista installation process to stop the entire drive being used, and as with XP, create a new partition after your XP partition. Choose Custom (Advanced) | Drive Options.
Click on the 'New' button on the 'Where do you want to install Windows?' window unless you've already created all the partitions you need. After installation, Vista will automatically add the boot menu to choose between the 'Earlier Version of Windows' (XP) and 'Microsoft Windows Vista', and the final step is to now install Linux into the remaining space.
Linux is last
We've used Ubuntu and Kubuntu in our example, but the vast majority of Linux installations will recognise your Windows installations without any manual intervention.
Ubuntu has a version of GPartEd built into the installation process and Live CD so that you can use this to resize your partitions before installing XP if you want to. When you return to install Linux, you will need to make a minimum of two extra partitions for the Linux installation.
Linux needs a swap partition that's usually around twice the size of your installed memory, and you will also need to create a root partition for the operating system. Make sure this is formatted using the 'etx3' filesystem (normally selected by default), and it uses a mount point of '/' for root.
You might also want to create an extra partition for your user's home directories - this is a good idea if you're forever upgrading your Linux version as a separate home partition means you can leave this partition untouched (along with all your personal data) and reformat and overwrite the root partition.
Lots of Linux distributions will simply find any alternative OSes installed, and add entries for these into the Linux boot menu. But there's something that's out of place; your Linux installation will see the Windows Boot Menu as a single operating system, and add this to the Grub/Lilo menu at boot time.
It will appear as 'Windows Vista/Longhorn Loader', and selecting this option will launch Microsoft's Boot Menu - so there are two layers of menus to use when booting into Windows. Aside from this, things will work as you expect, and you can now choose between XP, Vista and Linux on the same difference - the best of all worlds!
The full version of this article appears in issue 261 of PC Plus magazine.