Hard Drive caddy with xp pro

I have just bought a new computer with vista on it. I have an old hard drive with xp pro on it, i have put this hard drive in a caddy and tried to boot this drive through the USB.

XP pro begins to load then it goes into blue screen of death. I have run the chkdsk on the disk and it fixes any errors. I then have tried to run the xp repair on the caddy drive and it won’t register that there is xp on that hard drive.