The UI restore will only work if the backup was done using the UI or
appropriate
STSADM commands. Look at the file structure. It should have an XML
file
in the root, with a sub directory containing many .bak files. if this
structure does
not exist, you just see a .bak file, then the backup was likeley done
using an
SQL backup, so you need to restore using SQL restore.
Also, you can only restore the "FARM" if the backup was taken on that
original
farm and is being restored to the same farm since the configuration DB
is part of
the backup, and it has all the server names etc.