Vista - USMT2.UNC files

Hello,
It is not laziness that has brought me here, but absolute exasperation at
not finding a solution to a problem i have following an install of vista.
In short; Prior to trying vista 64 ultimate (and moving from xp 64) i did a
files and settings transfer on my existing setup to an external HD.
This was achieved using the xp software and the normal files and settings
transfer to a removable media but without the 'migwiz' files which i only
came across when i wanted to reinstate the files and settings on vista.
It may be poor management on my part, but i have been left with this
archive? USMT2.UNC of '.dat' files that i can not access! or reinstate! with
either xp or vista.
The file is about 45GB, and through having to manually make many settings on
this new OS, i no longer require all the settings from the older xp set up.
I have moved the file around quite a bit while trying different ways to
recover info from the archive and have tried using things like 'fastconv
utility' via the command prompt also without any success (extra work needed
as this extraction tool does not work on removable media).
The file is intact and i would really like to get some info from it if
anyone can help.
Please!!

Best regards