Installing OS (Win Xp) on an external USB HDD

Can anyone tell if its possible to install an OS onto an external hard drive (USB)? My friend asked if i can do it, but i dont want to have to pull my HDD out to put hers into my desktop.

Thanks

 

It's possible to install it to a USB flash drive, so it should be possible to install it to any USB storage device (except for external optical drives of course). Here's a how-to
http://www.tomshardware.com/2005/09/09/windows_in_your_pocket/page2.html
I've never done this but I know folks who have and it works. They've used this exact same guide so follow it carefully, print it if possible for close study. You'll need to download a few things (links are in the how-to), but after you get all the tools assembled, and you've studied the guide for a solid grasp of what's expected, it shouldn't be too tough. Just remember that this guide is for a USB flash drive, so it may be a bit different for an external USB hard drive.

 

:confused Hmmmmm.... I wonder how the OP is getting along with this project... I'm intertested to see how things turn out, and I'd like to know what worked, what didn't and how they got it all finished.... I'll subscribe to this one