Comment Try Equus (Score 1) 606
We use http://www.equuscs.com/ when Dell or HP don't fit a customer's needs.
As others have mentioned already you will need a volume license of windows if you want to transfer it. The nice thing about equus is that you can send them an image and any system you order from them will come with it preloaded. Oh and equus will be able to continue shipping XP Pro downgrade if you should need it.