I have a HP laptop with support for 3 USB 2.0 ports. I also have a clean 320Gb WD USB 2.0 drive. The HP can boot from USB (Bios options). I used the install disk (XP SP3 bootable) and after a few stutters, was actually able to load up a partition on the 320Gb drive with Windows. I cannot consistently get the system to boot up off the USB drive. I am able to drop Ubuntu on that same WD drive and boot up. I can even get Grub2 on Ubuntu to recognize the Win OS. But booting the Win OS is an impossible task. What can I do differently - if anything?