Thank your for getting back & very glad to hear you seem to have had success with creating a System Image, congratulations.

Have you tested whether you can actually do a Restore if needed. This Macrium website shows how to do that.

Restoring an image from within the Rescue Media - KnowledgeBase - Macrium Reflect Knowledgebase

Don't select the Finish button at the end, but click Cancel. Then remove your Rescue DVD, shut down the computer, disconnect your USB hard drive & the restart your computer.

NB. When the computer starts with the Rescue DVD it may take a few minutes to actually start to set everything up, so be patient.