Sure, if you want to run an OS other than Windows from the external drive. That's no problem, but Windows is designed NOT to be able to do this.
You could probably do it with Windows 3.1, if you could find USB drivers and integrate them into the image. From Win95 on though, forget about it.
Is it possible to dual boot frm an external USB HDD on a Win 7 platform?
My laptop lost its display and I bought a new desctop PC that came with Win 7.
I have an external usb drive enclosure and plan on mounting the laptop drive in it. This drive has Win XP, programs and my personal data files installed.
What would I have to do to make the machine to dual boot from it?