Due to these existing partitions, and a USB media card reader, the Windows XP installer would decide label it’s system partition “H:”, instead of the usual “C:”. I’m not sure how much this would have broken, but it annoyed me to the point that I found a hack to fix it.

I found that grub (the linux boot-loader) on my Linux partition allows you to edit the partition table and set the Vista NTFS partition to ‘hidden’. The XP installer could still see there was a partition there, but it didn’t understand it, and thus labelled it’s new partition “C:”. XP will of course then proceed to clobber your existing bootloader, but that’s a common occurrence, and fixable from a LiveCD, google is your friend here.

You should also be able to use a copy of grub on a LiveCD to mark the partition as (un)hidden if you don’t have Linux on your system normally.

Apologies for any vagueness and lack of technical details, this post has been on the back burner for a few months now, and I’ve actually forgotten most of the details.