booting windows 8 from external hard drive

Solution 1:

Apparently it's tricky to install Windows on a USB Hard Drive
Here is an article from 2008 on it
http://www.techspot.com/community/topics/how-to-install-and-boot-windows-on-an-external-usb-hard-drive.116114/

But you can get around that by using an image.
http://www.tomshardware.co.uk/forum/73631-35-install-windows-external-drive

I'd add, that you can use Macrium Reflect, to create and restore images, it is freeware,

Hello there. I have a simple solution for you if you are familiar with backup & recovery by acronis true image. Then step as bellow:
1. Install windows XP to your internal HDD
2. Make backup your windows XP by acronis true image
3. Create 1 primary partition in your external HDD
4. Recovery windows xp backup file which is already created in step 2 to primary partition in your external HDD.
5. Restart your laptop and press F12 key to get in menu boot select . Then select boot from external HDD

There may be a newer method , using diskpart and a VHD, which is mentioned at your link
http://dioisme.blogspot.com/2012/11/create-bootable-external-hdd-to-install.html

You can format it as FAT32, and you can always convert it to NTFS later. (I did that with XP).

Windows 7 has a convert command to do that (XP had too apparently) http://windows.microsoft.com/en-gb/windows7/convert-a-hard-disk-or-partition-to-ntfs-format

Solution 2:

This is definitely a workaround but if you can, put the external HDD into your PC or laptop so that it becomes internal, and install Windows 8 on it. Then remove the HDD and make it external again. Reboot from the external drive.

It boots just fine when I take a HDD with Windows 8 from a PC in my school and connect to my laptop.

My drives are in NTFS format.