I recently updated my wife's iMac to Lion. It was set up to dual boot with XP through Boot Camp from it's Snow Leopard days. I performed the upgrade with little trouble using a USB flash drive and the widely available online instructions. I was relieved to see that my XP partition was unharmed and I was able to load it without difficulty.
In my infinite stupidity, I decided it would be nice to have 3 partitions, OSX, XP, and some common area for mutual files. So I added a partition. -- Let me right now point out that there are many barriers to doing this, most of all the inability to efficiently and safely use any of the partition types across the two platforms - NTFS support in OSX is poor, and FAT32 is problematic for many reasons. The Mac formats are poorly supported in Windows. My advice would be to use an external drive (probably in NTFS with some third party support for OSX to be able to write to the disk). If there are any good suggestions, I'm happy to hear - I don't see why MS and APPLE can't play a little nicer together the only people benefiting from this are the third party software producers. I digress....
Anyway, the third partition messed up the dual boot configuration. I tried to fix this with reEFIt, and with the windows install CD - and I'm certain it was fixable, but I spent too long on it already so I decided to fix it by deleting all the partitions other than OSX. Done.
So I set out to reinstalling XP using Boot Camp. To my dismay, only windows 7 platforms are supported by Boot Camp in Lion. I started reading online and it seemed there were many problems with the XP-Lion setup not the least of which included no driver support for XP! Yikes.
Why XP you ask? Well, it still works pretty well for my needs. I'm sure Windows 7 is much better, but honestly the price is an absolute outrage!
All of this to say, I managed to get an XP - Lion dual boot running with little problem. Here's how:
1. With Disk Utility create a FAT32 partition for Windows. To do this you need to select the hard disk, then go to the partition tab and hit the plus button under the main partition. Choose the
2. Insert your XP CD and boot to the CD using the option key at startup or Command-C at startup.
3. Run the intall of XP (make sure you select the correct partition to install it on)
(also - don't reformat from the install if you want a partition >32gb in FAT32)
4. Once XP is installed you should be able to see it using the option key at startup.
5. Driver installation: you need to get your hands on the snow leopard or leopard drivers for your mac. These can probably be found online. I had the Snow Leopard disk that came with our computer handy, so I used that. I was able to install the drivers with little difficulty. This step is the key to making this all work, so if you don't have a PRE Lion install disk for your computer, make sure you can locate the necessary drivers before you start.
Hope this helps someone.
EDIT: Here is a link to a number of valuable driver downloads from Apple, this includes the range of available bootcamp drivers in separate packages. As far as I can tell, the 3.2 drivers (see step 5 above) are the last ones to support XP.