Dell laptop will not boot from cloned hdd via usb

[hotspur]

I have a Dell Inspiron 9300 and have cloned to an external hdd using Acronis True Image. When I try to boot from the HDD via the usb I get the blue screen. Any help appreciated

 

[hang-the-9]

You can't boot of a windows setup to a usb drive, you need to install the drive into the laptop.

 

[hotspur]

Thank you for your reply. The problem is that it is a 5.25" hdd, it is just a spare drive and I thought I would use it as a backup. The bios allows a boot up from a USB. I can boot to DOS from the CD. Thanks anyway

 

[hang-the-9]

You can boot from USB, but from a specially made USB boot device, not a regular Windows installation.

 

[hotspur]

What precautions can I take to restore my system in case of a hdd failure? As I mentioned I made a full acronis back up to a spare hdd but it appears this is not the solution, can you advise please?

 

[hang-the-9]

You can take an image, just restore it on the internal hard-drive, new or old one. You use the external drive just to hold the image files you make. If you just clone the drive instead of imaging it, make sure you clone it to a drive you can use in the laptop.