Access backed up registry?

Hi guys.I have recently made some changes to my registry and as a result I have some problems with my pc .Luckily  I have a full back up of my computer. So my question is, whether is it possible to access my old registry from the back up I've made, in order to see the changes I had made and recover them to their original state.
Generally how could I access my backed up registry :)
Thank you.