Windows with full hardware encryption on a laptop

Been preparing my laptop for the next project. Installed XP on an external usb using hardware encryption.
Currently the laptops internal disk carries Linux on a proprietary crypto system that I designed.
I made it company policy to have all clients data encrypted. Unfortunately XP does not have a satisfactory solution for this.
So here is my solution.
You see XP won't normally install on an external usb disk.
I wasn't given a recovery disk so what I did was copied the OEM i386 folder from the iso I made off the original hard disk.
Modified a few inf files.
Then made a new XP install disk from this collection.
Then installed the new system on the crypto external disk.

Works perfectly, Windows key , as recieved from the laptop maker.
So now I can carry my laptop round like normal and work on Linux. If a client requires me to demo/code on XP I can bring along the external and dual boot! All while keeping my privacy obligations.

Oh happy geekery.
I have a similar setup in my office, but using a separate partition. I also can boot the XP inside linux as a virtual machine using the disk as a raw image. However because I am in the graphics industry I sometimes need the raw Gpu power which a VM won't offer.