Restore/Backup problem

I backed my drive up to a large external drive prior to doing a (second) clean install. I changed the name of my system when I performed the clean install (no I do not know why I did this) and now although I can see all of the backed up zipped folders on the external drive, Vista Restore (either option) tells me that it can not see the media (or something like that). Does anyone have any idea on which file the drive and computer and user names are stored so that I can manually change them?

What did you use to do the backup with?

I should have provided a bit more information, sorry. I originally attempted an "upgrade" from XP Media to Vista HP. This did not work too well so I used the Vista "Backup / Restore" facility. Most of the installation did work so I was able to do this. The files all went over to my 1.5 tb external. I then performed a clean install which worked very well. In the process I renamed myself and my computer (small brain *&^). Now when I attempt to restore, the function says that the "media is not available..."

I can see all of the zipped files (hundreds of them) and I suppose that I can look into each but I am hoping that there is an xml file containing the computer name and other bits of info that I can change.

Thanks for the quick response.