Restoring image backup to bootable USB Flash Drive

I'm trying to build a bootable USB Flash Drive with an image backup that was restored to a flash drive.

The image backup was taken from a working installation of Windows XP Pro SP3 using Macrium Reflect free edition. The backup and restore operations both completed successfully.

I'm using a SanDisk Cruzer 64gb flash drive. All the files can be browsed on the flash drive, but the drive will not boot.

I get the BSOD whenever it tries to boot from that drive.

I've also tried with a different image backup that came from a disk with a clean installation of XP that came with a refurbished PC I bought. Same problem.

It could be just a problem with trying to boot from a USB device because I also tried to boot my clean install of XP hard drive connected via a USB interface to a machine with the same BSOD results.

I've tried booting from 3 different machines, so I don't think it's a hardware problem.

My research indicated it could be a problem with the NTLDR or boot.ini, so I've used Macrium Reflect Rescue disk to rebuild the boot.ini and MBR. Nothing seems to help.

I'd like to get this working so I know that my image backups are restorable.

The hardware I have available to me are a ThinkPad T41, ThinkPad T61, and eMachines desktop.

Thanks in advance for any help.
are you sure that the flash drive is bootable??

create an iso image of the install and then burn to the flash drive with rufus:

Download RUFUS 1.20 from here (read some stuff on the page so you can know more about it):

I will caution you to be careful that you don't accidentally format any of your hard drives - be sure your USB stick is in and know what the drive letter is! This part always makes me a little nervous, so be careful.

Launch RUFUS and all the defaults should be okay, for the Device, choose your USB drive letter, Quick format, FAT32, label it if you want to and in the Format options box, click the little icon that looks like a CD and a window will open.

navigate to where the iso image is located.

NOTE: you want to use the older version of rufus as the new versions do not work well with xp,

look at the link below for version 1.20
Thanks Elizabeth

I had come across this suggestion while searching the forum and wondered if it was applicable in my situation. I can try it, but have a couple of questions.

Shouldn't the restore process of an image backup of a bootable system disk make the restored media bootable? What process actually makes a flash drive bootable?

Also, if this is my problem - why couldn't I boot from my working external hard drive that has a clean install of XP on it when connected via a USB interface? I'm using a Kingwin EZ-CONNECT interface plugged into a 80GB SATA drive out of a Thinkpad T61. I can install this drive internally in my T61 and it boots, but won't via the USB interface.