database cluster missing

Hello I don't know where to start with this problem, so we do weekly
backups of our computers. The hard drive of one of our computers stopped
working so we are trying to restore it. We had an image of the hard drive
and used the latest backups. Now I can start the database without a
problem but it doesn't list any of the databases we had on it. Using
SELECT datname FROM pg_database ORDER BY datname returns no entries and
even if I connect using pgAdmin III I see no databases. The base directory
is about 21GB which is about the same that is was before the computer
crash. I don't know where to start, I try to google and look at some
threads but I couldn't find a similar issue. I tried pg_resetxlog -f, but
again the database starts find is just that it doesn't seem to be any
database in it.

thank you