Can you instal xp on a usb drive?

[Phil2008]

Im thinking about getting a 400 or 500gb drive and putting my old 200gb seagate drive in a USB External Enclosure and use it as my backup drive

But can I install and run xp ok frrom the usb drive? Cos I will need xp to restore partitions

 

[Phil2008]

I use Acronis TrueImage to backup my partitions,, thats why I want winxp on my backup drive so I can use Acronis TrueImage to do my partition backing up. I tried using my main drive with Acronis TrueImage but it needs to reboot into dos mode to restore the partiton, but Acronis TrueImage cant see my sata drive.