Posted 10 October 2010 - 11:47 AM
I've never booted linux distro...but MS has always suggested that the older version of Windows be installed first...then install the more recent version.
When you do this, the Vista bootloader will take over the booting of both Windows versions. Just an admin note but something to be aware if problems should develop with booting either version of Windows.
Personally...I would delete any partitions currently on the hard drive (assuming that you are installing both on same drive) and then just use the MS install CDs to install XP and Vista.
If you are using CDs which are not MS Genuine XP CDs (recovery/restore CDs provided by the system manufacturer), you need to be aware of the possibility of deleting necessary partitions by doing as I do and deleting all partitions prior to install.
I would also suggest adding a partition for data files, installing Windows and programs for that version...on the same partition. If you do that...and keep movies, pictures, etc. on the data partition, XP will be fine with a 20GB partition.